Given below are two statements: 

Assertion (A): Gases do not liquefy above their critical temperature, even on applying high pressure.
Reason (R): Above the critical temperature, the molecular speed is high and intermolecular attractions cannot hold the molecules together because they escape because of high speed.

1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true but (R) is not the correct explanation of (A).
3. (A) is true but (R) is false.
4. (A) is false but (R) is true.

Hint: Above the critical temperature, the molecular speed is high and the force of attraction is less.
 
Gases do not liquefy above their critical temperature, even an applying high pressure because above the critical temperature, the molecular speed is high and intermolecular attractions cannot hold the molecules together. Thus, liquefaction cannot takes place.
Hence, both assertion and reason are true and the reason is the correct explanation of assertion.