已知:Zn(s)+(1/2)O<sub>2</sub>--->ZnO,ΔcHm=351.5 kJ/mol Hg(l)+(1/2)O<sub>2</sub>---> HgO,Δ<sub>c</sub>H<sub>m</sub>= 90.8kJ/mol因此Zn+HgO --->ZnO+Hg 的Δ<sub>r</sub>H<sub>m</sub>是:()
A、442.2kJ/mol
B、260.7kJ/mol
C、-62.3kJ/mol
D、-442.2kJ/mol