Explanation:

1080 = 2³ * 3³ * 5. For any perfect square, all the powers of the primes have to be even numbers. So, if the factor is of the form 2^a * 3^b * 5^c.
The values 'a' can take are 0 and 2, b can take are 0 and 2, and c can take the value 0.
Totally there are 4 possibilities. 1, 4, 9, and 36.

The question is "How many factors of 1080 are perfect squares?"

Hence the answer is 4.

Choice A is the correct answer.