Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): Male frogs can be easily distinguished from female frogs externally. Reason (R): Male frogs possess sound-producing vocal sacs and a copulatory pad on the first digit of the forelimbs. In the light of the above statements, choose the most appropriate answer from the options given below:

Step-by-step solution

Assertion (A) is true because frogs exhibit clear sexual dimorphism, allowing males and females to be distinguished externally. Reason (R) is true because male frogs have specific external morphological features, namely sound-producing vocal sacs and a copulatory pad on the first digit of the forelimbs, which are absent in female frogs. Reason (R) correctly explains Assertion (A) as these specific structures are the exact criteria used for external distinction between the sexes. Therefore, both statements are true