What does a perfect square refer to in mathematics?

A perfect square in mathematics is defined as a number that can be expressed as the square of an integer. For instance, numbers like 0, 1, 4, 9, 16, and 25 are perfect squares because they can be obtained by multiplying an integer by itself (0x0, 1x1, 2x2, 3x3, 4x4, and 5x5, respectively).

This definition emphasizes that the square root of a perfect square will always be an integer, making option B the correct choice. While numbers that have a prime factorization or can be expressed as a fraction are important concepts, they do not specifically define perfect squares. The notion of a number being greater than 100 is also not relevant to the definition of perfect squares, as perfect squares can be less than 100 as well. Therefore, the focus on the requirement that a perfect square must have an integer square root is what categorizes option B as the correct answer.