Quantity A: The number of prime numbers between 1 and 100

There are 25 prime numbers between 1 and 100 and they are 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97.

Watch this video to know how to find the prime numbers between 1 and 100 quickly

Quantity B: The number of multiples of 3 between 1 and 100

Multiples of 3 between 1 and 100 are 3, 6, 9, ...., 99
Total Numbers = \(\frac{Last Term - First Term}{Common Difference}\) + 1 [ Watch this video to learn this formula ]
= \(\frac{99-3}{3}\) + 1 = \(\frac{96}{3}\) + 1 = 32 + 1 = 33

Clearly, Quantity B (33) > Quantity A (25)

So, Answer will be B.
Hope it helps!

Watch the following video to learn How to find Prime Numbers from 1 to 100