KBC 2023| Which of these is a prime number?

KBC 2023, Check the answer to the question- Which of these is a prime number?

KBC 2023, Amitabh Bachchan.
KBC 2023, Amitabh Bachchan. (Representative Image)

KBC 2023, The options to the question- Which of these is a prime number?

A. 11

B. 9

C. 15

D. 21

The answer is A. 11