If $\displaystyle\sum_{x \to \alpha} \begin{pmatrix}1 + \frac{a}{x} + \frac{b}{x^2} \end{pmatrix}^{2x} = e^2$ then the values of $a$ and $b$, are

Question

( A )
( B )
( C ) $a = 1$ and $b = 2$
( D )