10. Which properties were used to solve the following problem?

25(2x) + 25(3y)
(25 × 2)x + (25 × 3)y
(2 × 25)x + (3 × 25)y
50x + 75y

A. associative only
B. commutative only
C. both commutative and associative
D. neither commutative or associative