The amount of oxygen in the reactants is 4 atoms. in the products, the oxygen is distributed to water (h20) and o2 gas.
which coefficients would be placed in front of water and oxygen?
2 in front of water and 2 in front of oxygen
1 in front of water and 2 in front of oxygen
1 in front of water and 1 in front of oxygen
2 in front of water and 1 in front of oxygen

3 1/4

Explanation:

cause the 1 in front is bigger then the 2 in the back

2 in front of water and 1 in front of oxygen

Explanation:

There are 4 oxygen atoms in the reactants, so there will be 4 oxygen atoms in the products.

If you have 2 O₂ molecules, there won't be any oxygen atoms left for H₂O molecules.  So there must be a 1 coefficient in front of the O₂ product.

If there's 1 O₂, that leaves 2 oxygen atoms for water.  So there must be a 2 coefficient in front of the H₂O.