PLEASE HELP!! (will give brainliest for best answer)

Jillian said StartRoot 25 EndRoot is irrational because it is a square root. Why is she incorrect?

A) Jillian is incorrect because the square root of StartRoot 25 EndRoot = 5.5.
B) Jillian is incorrect because a square root is always rational.
C) Jillian is incorrect because square roots of perfect squares are rational.
D) Jillian is incorrect because the decimal expansion of StartRoot 25 EndRoot is a repeating decimal.