In 1938, a fish caught in South Africa turned out to be a Coelacanth,…

The correct answer is Option (1) → They were lobefins, which evolved into the first amphibians.

About 350 million years ago, fish with stout and strong fins could move on land and go back to water. These fish are called lobefins. The Coelacanth caught in 1938 was one of them; it had been thought to be extinct. Lobefins evolved into the first amphibians, which lived on both land and water. The amphibians later evolved into reptiles.

Option (1) They were lobefins, which evolved into the first amphibians. — Correct. The Coelacanth is a lobefin, and lobefins gave rise to the first amphibians, the ancestors of modern-day frogs and salamanders.

Option (2) They were jawless fishes, which evolved into the first amphibians. — Incorrect. Jawless fish are a different group of fishes. The Coelacanth, a fish with stout and strong fins, is a lobefin, not a jawless fish.

Option (3) They were lobefins, which evolved into the first reptiles. — Incorrect. The group is right, but the descendant is not. Reptiles evolved from the amphibians, not directly from the lobefins.

Option (4) They were jawless fishes, which evolved into the first reptiles. — Incorrect. Both parts are wrong: the Coelacanth is not a jawless fish, and reptiles came from amphibians, not from fishes.

NCERT Extract:
A Brief Account of Evolution – “… Jawless fish probably evolved around 350 mya. … Fish with stout and strong fins could move on land and go back to water. This was about 350 mya. In 1938, a fish caught in South Africa happened to be a Coelacanth which was thought to be extinct. These animals called lobefins evolved into the first amphibians that lived on both land and water. There are no specimens of these left with us. However, these were ancestors of modern day frogs and salamanders. The amphibians evolved into reptiles.”