Question Detail
Question
Which of the following is a reptilian feature of a prototherian mammal?
Correct Answer
Option B is the correct answer.
Detailed Explanation
Prototherians (monotremes like the platypus and echidna) are egg-laying mammals that retain several reptilian features. The presence of a cloaca (a common opening for the digestive, urinary, and reproductive tracts) is one such feature, as seen in reptiles, birds, and monotremes but not in other mammals (which have separate openings).
Hint
Think about the primitive mammalian group that lays eggs and shares this anatomical feature with reptiles.