Which of the following is true about lobefins like Coelacanth?

The correct answer is Option (4) - They were ancestors of modern day frogs.

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.