单项选择题

水的三相点附近,其汽化热和熔化热分别为44.82kJ/mol和5.994kJ/mol。则在三相点附近,冰的升华热约为:()

A.38.83kJ/mol
B.50.81kJ/mol
C.-38.83kJ/mol
D.-50.81kJ/mol