How many positive integers less than 100 are both multiples of 4 and perfect squares?

✓ Correct Answer: Option B

We need k² < 100, where k² is a multiple of 4. This implies k must be an even integer. Possible values for k are 2, 4, 6, 8. Their squares are 4, 16, 36, 64. All are less than 100 and multiples of 4. There are 4 such integers.