Answer: A. 336 square units
Explanation:
12 + 12 = 24 (Width)
10 + 18 = 28 (Height)
24 × 28 = 672 square units
12 × 10 = 120 square units ÷ 2 = 60 square units
18 × 12 = 216 square units ÷ 2 = 108 square units
672 - 60 - 60 - 108 - 108 = 336 square units