To answer this question, you need to understand different techniques used in software testing to achieve input and output coverage.
Option A) Boundary value analysis - This technique involves testing the values at the boundaries or limits of the input. It helps in identifying errors that occur at the edges of input domains. While boundary value analysis can help achieve input coverage, it does not specifically focus on output coverage.
Option B) Equivalence partitioning - This technique involves dividing the input data into different equivalence classes, where each class represents a unique behavior or outcome. By selecting a representative input from each class, you can achieve input coverage. Equivalence partitioning is commonly used to achieve input coverage.
Option C) Decision table testing - This technique involves creating a table that represents different combinations of inputs and their corresponding outputs. It helps in testing complex business rules or logic. While decision table testing can help achieve output coverage, it does not specifically focus on input coverage.
Option D) State transition testing - This technique is used to test the behavior of a system based on different states and transitions between those states. While state transition testing can help achieve input and output coverage, it is more focused on testing the transitions between states rather than covering all possible inputs and outputs.
The correct answer is Option B) Equivalence partitioning. This technique is specifically used to achieve input coverage by dividing the input data into different equivalence classes and selecting representative inputs from each class.