According to Bohr’s theory, the angular momentum of an electron in $5\text{th}$ orbit is:

According to Bohr's second postulate, the angular momentum ($L$) of an electron is quantized and is given by:
$$L=n\frac{h}{2\pi }$$
For the $5\text{th}$ orbit, $n=5$.
$$L=5\frac{h}{2\pi }=\frac{2.5h}{\pi }=\frac{h}{0.4\pi }\text{ (not in options)}$$
Wait, let's re-calculate: $L=\frac{5h}{2\pi }=\frac{h}{2\pi /5}=\frac{h}{0.4\pi }$.Looking at Option D: $\frac{h}{2.5\pi }$ would mean $L=\frac{1}{2.5}\frac{h}{\pi }=0.4\frac{h}{\pi }$.$5/2=2.5$. So $L=2.5\frac{h}{\pi }$.The mathematical expression $2.5\frac{h}{\pi }$ is equivalent to $\frac{h}{(1/2.5)\pi }$ or more simply just $2.5\times \frac{h}{\pi }$.The question format suggests $2.5\frac{h}{\pi }$.