Find the least common multiple of x 3 - x 2 + x - 1 and x 2 - 1. write the answer in factored form.
a. (x + 1) 2(x - 1)
b. (x + 1)(x - 1)(x 2 + 1)
c. (x 3 - x 2 + x - 1)(x 2 - 1)
d. (x + 1)(x - 1)(x 2 - 1)