Simplify the Complex Fraction $\frac{\frac{1}{a}+1}{\frac{1}{a}-1}$ A) $\frac{1+a}{1-a}$ B) $1-a^{2}$ C) 1
D) $\frac{a}{1-a^{2}}$

Simplify the complex fraction.
- $\frac{\frac{1}{a}+1}{\frac{1}{a}-1}$

A) $\frac{1+a}{1-a}$
B) $1-a^{2}$
C) 1
D) $\frac{a}{1-a^{2}}$