Given below are two statements: one is labelled as Assertion $(A)$ and the other is labelled as Reason $(R)$:
Assertion $(A):$ $A$ simple distillation can be used to separate a mixture of propanol and propanone.
Reason $(R):$ Two liquids with a difference of more than $20^{\circ}C$ in their boiling points can be separated by simple distillation.
In the light of the above statements,choose the most appropriate answer from the options given below:

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