If AB = BC, which of the following expresses the area of quadrilateral ABDE ?
A.fff\(\frac{a^{2}}{2}-\frac{b^{2}}{2}\)/fff
B.fff\(\frac{a}{2}-\frac{b^{2}}{2}\)/fff
C.fff\(a^2–b^2\)/fff
D.fff\(\frac{a^{4}}{4}-a\frac{b}{2}\)/fff
E.fff\(\frac{a^{4}}{4}+a\frac{b}{2}\)/fff
我的答案：
