Question

The greatest evolutionary change enabling the land vertebrates to be completely free from water, was the development of

• A. Four legs
• B. Lungs
• C. Shelled eggs and internal fertilization
• D. Four chambered heart

Answer 1

The correct option is C Shelled eggs and internal fertilization

• Shelled eggs (prevent the developing organisms from dehydration) and internal fertilization (chances of survival are high) made survival on land possible.
• Thus, oviparous and viviparous organisms came into existence.