Let n be a positive integer such that In = ∫xn√(a2 - x2)dx. Then answer the following questions:
If In = (-xn-1(a2 - x2)3/2)/(n + 2) + kln - 2, then the value of k is
(A) (n - 1)/(n + 2)
(B) (n + 2)/(n - 1)
(C) ((n - 1)/(n + 2))a2
(D) ((n + 2)/(n - 1))a2