Q.Which of the following is an egg laying mammal?
a. Delphinus
b. Macropus
c. Ornithorhynchus
d. Equus

Step 1. Almost all mammals are viviparous (give birth to live young), but the chapter specifically lists an oviparous (egg-laying) exception: Ornithorhynchus, the platypus.

Step 2. The platypus belongs to the monotremes, a small group of mammals that retained egg-laying reproduction while still possessing the two defining mammalian features — hair and mammary glands. …

Recall the chapter's specific example of an oviparous mamma …

• Assuming all mammals must be viviparous, since that is the pattern for …