The complex exponential power form of Fourier series of x(t) is \(x\left( t \right) = \mathop \sum \limits_{k = - \infty }^\infty {a_k}{e^{j\frac{{2\pi }}{{{T_0}}}kt}}\)If \(x\left( t \right) = \mathop \sum \limits_{b = - \infty }^\infty \delta \left( {t - b} \right)\), then the value of ak is :

• A. 1 - (-1)k
• B. 1 + (-1)k
• C. 1
• D. -1