FERMAT 2005 Problem 20

In triangle A B C, if A B=A C=x+1 and B C=2 x-2, where x>1, then the area of the triangle is always equal to

Answer Choices
A. (x-1) \sqrt{2 x^2+2}
B. 2(x-1)
C. \frac{1}{2}(x+1)^2
D. (x+1)(x-1)
E. 2(x-1) \sqrt{x}