Assertion (A) van der Waals' forces are reponsible for chemisorptions.Reason (R) High temperature is favourable for chemisorptions. The correct answer is

• Correct answer
  A

  (A) is false, but (R) is true
• B

  Both $(A)$ and $(R)$ are correct and $(R)$ is the correct explanation of $\mathrm{A}$
• C

  Both $(A)$ and $(R)$ are correct and $(R)$ is not the correct explanation of (A)
• D

  (A) is true, but (R) is false

Hence, the correct answer is option: 'A'.