Final answer:
A program with high cyclometric complexity is difficult to test.
Step-by-step explanation:
A program with high cyclometric complexity is almost likely to be difficult to test. The cyclometric complexity of a program is a measure of how many different paths there are through the code. So a program with high cyclometric complexity is likely to have many different paths, which makes it more difficult to test because you need to test each possible path to make sure the program functions correctly.
For example, imagine a program that includes lots of if statements and loops with different conditions. Each possible condition creates a new path through the code, and testing all of these different paths can be time-consuming and complex.
Therefore, the correct answer to the question is D. Difficult to test.