A. 3
B. 5
C. 7
D. 9
Answer
Correct Answer: D. 9
Solution
A prime number is a positive integer greater than 1 that has no positive integer divisors other than 1 and itself.
Out of the options given, 9 is not a prime number because it has three positive integer divisors: 1, 3, and 9. Therefore, the answer is D. 9.