Choose the correct explanation as to why the changing of a subscript on a substance is not allowed when balancing a chemical equation.

The subscript of a substance is not altered when balancing a chemical equation because this will make it harder to balance the number of each kind of atom.

The subscript of a substance is not altered when balancing a chemical equation because this would change the identity of the substance.

Changing the subscript of one substance will require changing the subscripts of the other substances also.

The subscript of a substance is generally not altered when balancing a chemical equation, except when the number of hydrogen and oxygen atoms are being balanced.