Answer: c. so that you use the correct energy states
Step-by-step explanation:
Enthalpy is the energy release or energy produced when a chemical reaction is carried out.
Enthalpy change is calculated by substracting the energy of reactants from the energy of products.
![\Delta H=H_(products)-H_(reactants)](https://img.qammunity.org/2022/formulas/chemistry/high-school/89mwsjdjqai935kh0o9m2qpcul8ogazzn8.png)
As the energies are different for different states and thus the correct stale symbols in your balanced chemical equation must be given so that we use the correct energy values.