The following two questions consist of two statements – Assertion (A) and Reason (R). Answer these questions by selecting the appropriate option given below:

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

B. Both A and R are true, and R is not the correct explanation of A.

C. A is true but R is false.

D. A is false but R is true.

Assertion (A): The rate of breathing in aquatic organisms is much lower than in
the terrestrial organisms.

Reason (R): The amount of oxygen dissolved in water is less as compared to
the amount of oxygen in air.