The answer is A.
This is saying 5E-9/2E4, so it equals 2.5E-13.
surface area = 4 x pi x r^2
diameter = 1 so radius = 1/2 = 0.5
4 x 3.14 x 0.5^2 = 3.14 meters^2
B because it obviously can’t be any other
It represents the distance diagonally between two opposite corners of a Television. (i.e. the distance between the bottom-left corner and the top-right corner)