Java Programming and Early Languages

The valid scopes for jsp:useBean are page, request, session, and application. 'context' is not a valid scope value - it should be 'application' for application scope. Option C correctly identifies 'context' as invalid.

Option B is correct - jsp:include action with page attribute is valid JSP syntax. Option D has a typo 'inlcude' but is meant to represent the include directive with file attribute, which is valid syntax. Option A uses page with directive (wrong), and C uses action with file (wrong - should be page).

Implementing the Runnable interface is preferred over extending the Thread class in Java because Java does not support multiple inheritance. By implementing an interface, the class remains free to inherit from another class. This approach also promotes better separation of concerns between the task execution logic and the thread mechanism.

JSP implicit objects are: request, response, pageContext, session, application, out, config, page, exception. 'context' is NOT an implicit object - the correct name is 'application' for the ServletContext reference.

Abstract classes can have both abstract methods (without implementation) and concrete methods (with implementation). This allows partial implementation - some methods are implemented, others are left abstract for subclasses to implement. Interfaces require all methods to be implemented by the implementing class, and concrete classes must provide complete implementation.

Inheritance is a core OOP concept where a class derives properties and behavior from another class. The other options are not OOP concepts: Exception is a programming error handling mechanism, deadlock is a concurrency problem, Thread is about concurrent execution, and Networking deals with communication between systems. The question asks for OOPs concepts (plural) but only marks one option as correct, which is confusing.

GenericServlet is an abstract class in Java Servlet API that implements the Servlet interface. It provides basic implementation of most Servlet methods except service(), which must be implemented by subclasses. HttpServlet extends GenericServlet to provide HTTP-specific functionality. GenericServlet is not an interface, not a concrete class, and not a Filter.

The valid scope values for jsp:useBean are: page (default), request, session, and application. 'context' is NOT a valid scope value. Option C is correct because 'context' is invalid. Option F claims both 'context and application' are invalid, but 'application' IS valid, so F is incorrect.

Implementing Runnable interface is preferred over extending Thread class because Java supports only single inheritance - by implementing Runnable, your class can still extend another class if needed. It also separates the task logic from the thread execution mechanism, following better object-oriented design principles. Extending Thread should only be used when you need to override Thread methods other than run().

JSP implicit objects are automatically available in JSP pages without declaration. The standard implicit objects are: request, response, pageContext, session, application (not 'context'), out, config, page, and exception (only in error pages). 'context' is not a valid implicit object name - the correct names are 'application' for servlet context and 'pageContext' for page context.

Abstract classes are designed specifically to provide partial implementation - they can have both abstract methods (without implementation) and concrete methods (with implementation). Interfaces require all methods to be implemented (before Java 8) and regular classes must provide complete implementations. Only abstract classes allow the flexibility of implementing some methods while leaving others for subclasses to complete.

FORTRAN (Formula Translation) was the first successful high-level programming language, developed in 1957 by IBM for scientific and engineering calculations. C and C++ came much later (1970s and 1980s), while QBASIC is a dialect of BASIC from the 1980s.

Edsger W. Dijkstra was a pioneering computer scientist who contributed to the ALGOL programming language design and developed the famous shortest path algorithm (Dijkstra's algorithm). ALGOL introduced structured programming concepts that influenced later languages like Pascal and C. Charles Babbage preceded this era by a century, while Noyce and Moore were integrated circuit pioneers.