Which of the following is a composite number?

A. 91

B. 29

C. 13

D. 139

The number 91 is divisible by 1, 7, 13 and 91. Therefore 91 is composite since it has more than two factors.

13 is a prime number as it is divisible by only 1 and itself.

29 is a prime number as it is divisible by only 1 and itself.

139 is a prime number as it is divisible by only 1 and itself

91 is a composite number because it divisible by 1, 7, 13, and 91.

Your answer is A. 91