We know that, (A) Phenomenon of conversion of liquid into solid is known as fusion. (B) Phenomenon of conversion of liquid into vapour is known as vaporisation. (C) Phenomenon of conversion of solid into vapour directly without going to liquid state is known as sublimation. (D) Phenomenon of melting of ice caused by pressure is known as regelation. Hence, the correct match is A→3,B→4,C→2 and D→1