Casey wants to put new carpet in her bedroom. A drawing of Casey's room is below. It consists of two sections: a square and a rectangle.

The rectangular section has the same width as the square section, but twice the length. If one side of the square section measures 4 yards, how many square yards of carpet should Casey buy for her room?
A.
32 square yards
B.
18 square yards
C.
36 square yards
D.
48 square yards