Energy is used up. Cellular respiration is a process where energy is transferred, so it would incorrect to say that energy is used up.
Cellular respiration is the process where energy is converted into ATP, and eventually is expelled as waste. ATP is the food of cells providing energy. ATP is created from oxygen and sugar, so we can eliminate the first choice. However, in order for the sugar to be converted into ATP with oxygen, it must be broken down. We can eliminate the third choice. We can also eliminate the second choice because the energy molecule it is referring to is the ATP, and ATP does transfer energy to the cells.
Hope this helps!
