Which two expressions are equivalent?

A. 7(3 + x) and 7∙ 3 + 3 ∙ x
B. 7 + 3 + x and (7 + 3) + x
C. 7 ∙ x ∙ 3 and 7(x + 3)
D. 7 ÷ (3 – x) and 7 ÷ (x – 3)