2c6h5cooh + 15o2 → 14co2 + 6h2o which of the following options gives the correct product: product ratio?

You did not include the options but I can tell you the product ratio.

The product ratio is the mole ratio of the products of the reaction.

From the balanced chemical equation you have all the mole ratios:

The given equation is: 2 C6H5COOH + 15O2 --> 14 CO2 + 6H2O

The mole ratios are: 2 C6H5COOH: 15 O2: 14 CO2 : 6 H2O

The products are CO2 and H2O

Their mole ratio = 14 CO2 : 6 H2O

That can be expressed as:

14 mol CO2        7 mol CO2
= 
  6 mol H2O        3 mol H2O

It is also the same that:

6 mol H2O : 14 mol CO2

  6 mol H2O           3 mol H2O
= 
14 mol CO2           7 mol CO2

So, compare your options to the ratios show above and pick the proper ratio.