Choose the equation with the correct grouping symbols.

A. 45 + 45 ÷ (3 ÷ 3) = 20
B. 45 + [45 ÷ (3 ÷ 3)] = 20
C. [45 + (45 ÷ 3)] ÷ 3 = 20
D. 45 + (45 + 3 ÷ 3) = 20