Solve this following

Mark $(\sqrt{ })$ against the correct answer in the following:

If $y=2^{x}$ then $\frac{d y}{d x}=$ ?

A. $\mathrm{x}\left(2^{\mathrm{x}-1}\right)$

B. $\frac{2^{x}}{(\log 2)}$

C. $2^{x}(\log 2)$

D. none of these