Hey there!
C₉H₂O + O₂ → CO₂ + H₂O
First let's balance the C.
There's 9 on the left and 1 on the right. So, let's add a coefficient of 9 in front of CO₂.
C₉H₂O + O₂ → 9CO₂ + H₂O
Next let's balance the H.
There's 2 on the left and 2 on the right. This means it's already balanced.
C₉H₂O + O₂ → 9CO₂ + H₂O
Lastly, let's balance the O.
There's 3 on the left and 19 on the right. So, let's add a coefficient of 9 in front of O₂.
C₉H₂O + 9O₂ → 9CO₂ + H₂O
This is our final balanced equation.
Hope this helps!

This reaction is called decomposition reaction, furthermore it can be said to be decomposition of limestone.
The balanced chemical equation for the reaction is ~

Answer:
c. stays the same, changes
Explanation:
temperature and heat go hand in hand, however while the change of state occurs, the temperature remains the same while the heat increases since the heat input is constant.