Assertion (A): The excretory product of lizards is uric acid.
Reason (R): Lizards show terrestrial habitat.

Options

A. Both A and R are true and R is the correct explanation for A.
B. Both A and R are true but R is not the correct explanation for A.
C. A is true and R is false.
D. A is false and R is true.

Explanation

Terrestrial adaptation requires the production of less toxic nitrogenous wastes like urea (ureotelic) and uric acid (uricotelic) for the conservation of water. Aquatic lizards excrete ammonia which requires large amount of water to dissolve. The huge quantity of water is easily available to such animals from surroundings. However, for terrestrial animals such a huge quantity of water is not available, hence they modify comparatively less toxic products like urea and uric acid which require less amount of water for their excretion.
Hence, the correct option is (a).