Which of the following pairs of morphological features can be used to externally distinguish a male frog from a female frog?

Step-by-step solution

In frogs, sexual dimorphism is clearly visible externally. Male frogs can be distinguished from female frogs by the presence of sound-producing vocal sacs and a copulatory pad on the first digit of the forelimbs. Both of these structures are absent in female frogs. Tympanum, webbed feet, and nictitating membranes are morphological features present in both male and female frogs. The copulatory pad is specifically located on the forelimb, not the hind limb. Answer: Sound producing vocal sacs and a copulatory pad on t