Assertion $(A)$: There is a considerable increase in covalent radius from $\mathrm{N}$ to $\mathrm{P}$. However from $As$ to $Bi$ only a small increase in covalent radius is observed.
Reason $(R)$: covalent and ionic radii in a particular oxidation state increases down the group.
In the light of the above statement, choose the most appropriate answer from the options given below:
- A$(A)$ is false but $(R)$ is true
- ✓Both $(A)$ and $(R)$ are true but $(R)$ is not the correct explanation of $(\mathrm{A})$
- C$(A)$ is true but $(R)$ is false
- DBoth $(A)$ and $(R)$ are true and $(R)$ is the correct explanation of $(A)$
