In which chemical equation is the number of atoms in the reactants, the same as the number of atoms in the products

A Zn+2HCI->H2+ZnCI2
B CO2+H2O->CH2OH+O2
C Li2CO->LiO+CO2
D CH4+O2->CO2+2H2O

The chemical equation in which the number of atoms in the reactants is the same as the number of atoms in the products is D: CH4 + O2 -> CO2 + 2H2O.

In this equation, there is 1 carbon atom and 4 hydrogen atoms in the methane (CH4) reactant, which matches the 1 carbon atom and 4 hydrogen atoms in the carbon dioxide (CO2) and water (H2O) products.