Which one of the following is a prime number ?

Question:
Which one of the following is a prime number ?

[A].

161

[B].

221

[C].

373

[D].

437

Answer: Option C

Explanation:

437 > 22

All prime numbers less than 22 are : 2, 3, 5, 7, 11, 13, 17, 19.

161 is divisible by 7, and 221 is divisible by 13.

373 is not divisible by any of the above prime numbers.

373 is prime.