Thank you sa points lab you
I think the answer is C. (a.k.a the third one)
I hoped this helped !!
The absolute value of a real number is a positive value of the number. Which means that the absolute value is the distance from zero of the number line. However, that of the complex numbers is the distance from the origin to the point in a complex plane.
Use a=

r^2 (r represents your radius of 4 feet)

(4^2)
Answer = 16

^2