Add or Subtract as Indicated $\frac{2 a b}{a^{2}-b^{2}}-\frac{b}{a-b}+4$ A) $\frac{2 a b-b+4}{a+b+1}$

Add or subtract as indicated. Write the answer in lowest terms.
- $\frac{2 a b}{a^{2}-b^{2}}-\frac{b}{a-b}+4$

A) $\frac{2 a b-b+4}{a+b+1}$

B) $\frac{(a-b) (5 a+5 b) }{a^{2}-b^{2}}$

C) $\frac{4 a+5 b}{a+b}$

D) $\frac{4 a+5 b}{a^{2}-b^{2}}$