[单选题]
For the combustion of magnesium, which of tz9,: o9/rn(wv6s6kyyy0p3 phcdjb cfhe following are 1ho-z-1hqm h q4ptn+;iak oy :correct for the producz y4:k1 1ho+ ihohqaq;pn-t -mts and enthalpy of reaction?
Mg(s)+$O_2$(g)→? ΔH?
A. $MgO$;ΔH>0
B. $MgO_2$;ΔH>0
C. $MgO$;ΔH<0
D. $MgO_2$;ΔH<0
