Question #N206

The expression $\frac{x^2 + 3x - 4}{x^2 - 1}$ is equivalent to which of the following?
A. $\frac{x-4}{x-1}$
B. $\frac{x-1}{x+1}$
C. $\frac{x+4}{x+1}$
D. $\frac{x+4}{x-1}$