Answer:
C. 14 ft by 21 ft
Explanation:
First you want to set up an equation:
3 1/2" over x' = 1/4" over 1'
7/2 = 1/4x
14' = x
Next, do the same thing for the other side of the drawing (5 1/4")
5 1/4" over y' = 1/4" over 1'
21/4 = 1/4y
21' = y
So the answer is 14 ft by 21 ft (C)