Ans. (D). Energy is produced and stored during cellular respiration.
Oxidation of glucose during cellular respiration is better than burning of coal in the presence of oxygen. It is because burning coal generates heat, which is not generally useful and cannot be captured by cells as energy source.
On the other hand, cellular respiration involves complete oxidation of glucose, which provides so much energy. This energy is stored by the cell for its cellular activities.
Thus, the correct answer is option (D).