Identify the mammals which live wholly in water:

A. Dolphins
B. Seals
C. Sea Horse
D. Sea cow

Choose the correct answer from the options given below:

A and D only

The correct answer is Option (4) → A and D only

Dolphins (A), seals (B), and sea cows (D) (also known as manatees) are all mammals that live wholly or primarily in water.

Dolphins live in the world's seas and oceans and in some rivers too. Some dolphin species prefer to live in coastal areas, others like shallow water which are located further out to sea.

Sea cows are herbivorous aquatic animals hence the name sea cow. The other name for Sea Cow is Stellar’s Sea Cow and is now extinct.

Seals are semi-aquatic and also live partially on land but spend significant portions of their lives in water.

Sea horse (C), however, is a bony fish, not a mammal, and does not belong in the category of mammals that live in water.