已知：

(1) Zn(s) +l/2O₂(g)=ZnO(s)；△H= - 348. 3 kJ/mol

(2) 2Ag(s) +1/2O₂(g)=Ag₂O(s)；△H= -31.0 kJ/mol

则Zn(s) +Ag₂O(s)=ZnO(s) +2Ag(s)的△H等于 [ ]

A．-317. 3 kJ/mol

B．- 379.3 kJ/mol

C．- 332. 8 kJ/mol

D．317.3 kJ/mol