You can put this solution on YOUR website!
The area of a circle is given by:
Replace r with D/2 since the problem gives you the diameter, D.
Substitute D = 42 inches.
sq.in. Now convert this to square feet by dividing by 144 sq.in. per sq.ft.
I just don't see this answer in your list of choices. Your answer A) has the right number but the wrong units, so answer A) would be correct if it were square inches. rather than square feet.