KBC 2023| Which of these is a prime number? KBC 2023, Check the answer to the question- Which of these is a prime number? By Alana Mohammed Ali Cholassery - August 21, 2023 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