Which of the following shows a physical change?
A. H2(g)+O2(g)=H2O(l)
B. 2CH3OH(l)+3O2(g)=2CO2(g)+4H2O(l)
C. NaCl(s)=NaCl(aq)
D. 2AgNO3(aq)+CaBr2(aq)=2AgBr(s)+Ca(NO3)2(aq(