Given below are two statements: one is labelled as Assertion $(A)$ and the other is labelled as Reason $(R).$
Assertion $(A):$ Lithium salts are hydrated.
Reason $(R):$ Lithium has higher polarising power than other alkali metal group members.
In the light of the above statements,choose the most appropriate answer from the options given below:

• A
  Both $(A)$ and $(R)$ are correct but $(R)$ is $NOT$ the correct explanation of $(A).$
• B
  $(A)$ is correct but $(R)$ is not correct.
• C
  $(A)$ is not correct but $(R)$ is correct.
• D
  Both $(A)$ and $(R)$ are correct and $(R)$ is the correct explanation of $(A).$