Rabbits cannot survive in an aquatic habitat because they have

Analyze the question: It asks why rabbits cannot live in water. The answer should be the adaptation they lack that is essential for aquatic life, namely the structure that allows underwater gas exchange.

Explain the concept: Aquatic animals such as fish need adaptations for life in water:

• Gills extract dissolved oxygen from water (respiration)
• Fins help with swimming and balance
• Scales protect the body and reduce friction

Rabbits are terrestrial mammals. They breathe with lungs, which take in oxygen from air, not from water.

Step-by-step solution:

• A. fore and hind limbs: Many aquatic animals, such as frogs and turtles, also have limbs, so this does not prevent aquatic life. It is not the reason.
• B. no gills: Without gills, a rabbit cannot get oxygen from water and would drown. This is the fundamental, life-limiting reason.
• C. no fins: Lacking fins makes swimming harder, but many aquatic animals, like whales and dolphins, have flippers rather than true fins. Rabbits can even swim a little, so fins are not the critical factor.
• D. no scales: Many aquatic animals, such as frogs and whales, have no scales, so this is not the reason.

The most important factor is respiration. Without gills, a rabbit cannot breathe underwater.

Answer: B. no gills

Exam tip: In "cannot survive in water/land" questions, think first about respiration. Oxygen supply decides survival. Locomotion and protection are secondary. Remember: Gills for water, lungs for air.