A thin piece of wire 40 meters long is cut into two pieces. One piece is used to form a circle with radius r, and the other is used to form a square. No wire is left over. Which of the following represents the total area, in square meters, of the circular and the square regions in terms of r?
A. π x r^2
B. π x r^2 + 10
C. π x r^2 + 1/4 x π x r^2
D. π x r^2 + (40 - 2 π x r)^2
E. π x r^2 + (10 - 1/2 π x r)^2