Given below are two statements. One is labelled Assertion (A) and the other is labelled Reason (R).

Assertion (A): Respiration involves catabolic reactions.
Reason (R): Energy is released by the breakdown of simple molecules like glucose, amino acids and fatty acids in cells.

In light of the above statements, choose the correct answer from the options given below. 

Both A and R are true and R is the correct explanation of A.

Respiration involves catabolic reactions. During respiration, energy is released by the breakdown of complex organic molecules such as glucose, amino acids, and fatty acids in cells. These molecules are broken down through catabolic processes such as glycolysis, the citric acid cycle, and oxidative phosphorylation, ultimately leading to the production of ATP, which is used as energy currency in the cell.