AHSME 1979 Problem 1

If rectangle ABCD has area 72 square meters and E and G are the midpoints of sides AD and CD, respectively, then the area of rectangle DEFG in square meters is $\textbf{(A) }8 \textbf{(B) }9 \textbf{(C) }12 \textbf{(D) }18 \textbf{(E) }24$