Which of the following is a balanced chemical equation?

MgF2 + Li2CO3 ⟶ MgCO3 + LiF
CH4 + 2O2 ⟶ CO2 + H
2Al + 6HCl ⟶ 3H2 + AlCl3
P4 + 3O2 ⟶ 2P2O3