The second order derivative of which of the following functions is $$5^x$$​?

Correct option is D

​$$\begin{aligned}&\frac{d}{dx} \left( \frac{5^x}{(\log_e 5)^2} \right) = \frac{5^x \log 5}{(\log_e 5)^2} = \frac{5^x}{\log 5} \\&\text{Again, differentiating} \\&\frac{d^2}{dx^2} \left( \frac{5^x}{\log 5} \right) = \frac{5^x \log 5}{\log 5} = 5^x\end{aligned}$$​​