(A) : Greater the value of Vander Waals constant ‘a’ greater is the liquification of gas.
(R) : ‘a’ indirectly measures the magnitude of attractive forces between the molecules.

Both (A) and (R) are correct and (R) is the correct explanation of (A)

(A) is True but (R) is False.

Both (A) and (R) are false

Both (A) and (R) are correct but (R) is not the correct explanation of (A)