Question

when two intermediate chemical equations are combined, the same substance that appears in the same phase can be canceled out, provided that
it is a reactant in one intermediate reaction and a product in the other
it is a reactant in both of the intermediate reactions.
it is a product in one intermediate reaction and a catalyst in the other reaction.
it is a reactant in one intermediate reaction and a catalyst in the other reaction.

Explanation:

When combining chemical equations, a substance can be canceled out if it is a reactant in one intermediate - reaction and a product in the other. This is because it is consumed in one step and produced in another, effectively not being part of the overall reaction.

Answer:

It is a reactant in one intermediate reaction and a product in the other