To solve this question, the user needs to understand the structure of a PL/SQL block and the purpose of each section.

The PL/SQL block is divided into the following sections:

1. Header: This section is optional and contains comments and declarations of global variables and cursors.

2. Declarative: This section is optional and contains declarations of local variables, cursors, types, and subprograms.

3. Executable: This section is mandatory and contains the code that performs the desired operations.

4. Exception: This section is optional and contains handlers for exceptions that may be raised during the execution of the executable section.

The correct answer is:

D. Exception

Functions for error trapping are contained in the exception section of a PL/SQL block. This section contains handlers for exceptions that may occur during the execution of the executable section. These handlers allow the program to gracefully handle errors and continue executing, rather than crashing or terminating unexpectedly.

To solve this question, the user needs to know the correct SQL syntax for getting the total value of a column in a table. The correct SQL syntax for getting the total value of a column in a table is to use the SUM() function.

Now, let's go through each option and explain why it is right or wrong:

A. SELECT ADD(Price) FROM Sales: This option is incorrect because there is no ADD() function in SQL. The user should have used SUM() instead of ADD().

B. SELECT SUM(Price) WHERE Sales: This option is incorrect because the WHERE clause is incomplete. The correct SQL syntax would be to use the FROM keyword after the WHERE clause to specify the table from which to retrieve the data. Additionally, the correct SQL syntax for getting the total value of a column is to use the SUM() function, not the WHERE keyword.

C. SELECT TOTAL(Price) FROM Sales: This option is incorrect because there is no TOTAL() function in SQL. The user should have used SUM() instead of TOTAL().

D. SELECT SUM(Price) FROM Sales: This option is correct. The user has used the correct SQL syntax to get the total value of the 'Price' column in the 'Sales' table. The SUM() function is used to add up all the values in the 'Price' column and return the total value.

The Answer is: D

To count the rows in a table, we use the COUNT() function in SQL. The correct answer is:

The Answer is: A. SELECT COUNT(*) FROM Sales

Explanation:

A. SELECT COUNT() FROM Sales: This option is correct because it uses the COUNT() function to count all the rows in the 'Sales' table. The () symbol means that we are counting all the rows.

B. SELECT COUNT(*) IN Sales: This option is incorrect because the syntax is not correct. The keyword IN cannot be used in this context.

C. SELECT COUNTER(*) FROM Sales: This option is incorrect because there is no such function as COUNTER() in SQL. The correct function name is COUNT().

D. SELECT NUM() FROM Sales: This option is incorrect because there is no such function as NUM() in SQL. We need to use the COUNT() function to count the rows in the table.

Therefore, option A is the correct answer.

To solve this question, we need to trace the execution of the code and see how the value of the variable s changes.

Starting with the main method, it creates a new instance of the Plane class and calls its method s1().

In the s1() method, it calls the method sl().

In the sl() method, it calls the method s2(). Since s2() throws an exception, execution of the sl() method is transferred to the catch block. Here, it appends "c" to the value of s.

Control is then transferred back to the s1() method, which then returns to the main method. Finally, the value of s is printed to the console, which is "-c" since the catch block was executed.

Therefore, the answer is: B. -c