Select the answer with a rational product and a correct explanation for why the product is rational.

Question

√5 ⋅ √125, because the product of two irrational numbers is always a rational number.

(0.777...) ⋅1921, because the product of a repeating decimal and a rational number is always a rational number.

5 over pi times pi, because the product of a fraction and an irrational number is always a rational number

1/7 ⋅ √36, because the product of a fraction and a square root is always a rational number.

Answer 1

1/7 ⋅ √36, because √36 is equal to 6, which is a rational number.