Which of the following equations represents a double-displacement reaction?
A. FeS(s) + 2HCl(aq) ® H2S(g) + FeCl2(aq)
B. 2Sb(s) + 3I2(g) ® 2SbI3(s)
C. Zn(s) + H2SO4(aq) ® ZnSO4(aq) + H2(g)
D. 2HgO(s) ® 2Hg(l) + O2(g)