Forelimbs of frogs have-
A. Five digits
B. Four digits
C. Three digits
D. One finger

Hint: Frog, scientifically named Rana tigrina, from the order Anura belongs to class amphibia of phylum Chordata. They are widely present in the areas ranging from tropical to subarctic regions, maximum of them are concentrated in the tropical rainforest. An adult frog has a stout body with protruding eyes, a tongue which is anteriorly attached, and no tails. They have glandular skin. Their habitat is freshwater and on dry land; some live underground also.

Complete answer:
The skin of frogs is smooth and slippery due to the presence of mucus. They never drink water but absorb it through their skin. The body of a frog is divisible into two parts: head and trunk. A pair of nostrils is present above the mouth. Their eyes bulge and a protective covering is present over there called a nictitating membrane that protects them in water. Frogs have a tympanum that represents their external ears to receive external sound vibrations. Their forelimbs and hind limbs help in leaping, swimming, burrowing, and walking. The hind limbs of frogs have five digits while the forelimbs end in four digits. Hind limbs are more muscular and larger when compared to forelimbs.
Hence, the correct option here is option (B).

Note: The feet of frogs have webbed digits that facilitate them during swimming. Male frogs are differentiated from female frogs in having copulatory pads on the first digit of the forelimbs. They have a radius and ulna in their forelimbs. All the digits are without nails. Generally, the forelimbs of frogs are comparatively short but in arboreal frogs they are relatively long.