a) Customer can respond to each increment
b) Easier to test and debug
c) It is used when there is a need to get a product to the market early
d) Easier to test and debug & It is used when there is a need to get a product to the market early

Answer: d
Explanation: Incremental Model is generally easier to test and debug than other methods of software development because relatively smaller changes are made during each iteration and is popular particularly when we have to quickly deliver a limited functionality system.However, option “a” can be seen in other models as well like RAD model,hence option “d” answers the question.