The finches found on Galapagos Islands were originally __________.

The correct answer is Option (4) → Seed eaters

Option (4) Seed eaters — Correct. Darwin saw many kinds of finches on the Galapagos Islands. They had all evolved from seed-eating ancestors; other forms with changed beaks later arose, such as insect eaters and vegetarian finches. This is adaptive radiation.

NCERT Extract:
What Is Adaptive Radiation? – “… All the varieties, he conjectured, evolved on the island itself. From the original seed-eating features, many other forms with altered beaks arose, enabling them to become insectivorous and vegetarian finches (Figure 6.5). This process of evolution of different species in a given geographical area starting from a point and literally radiating to other areas of geography (habitats) is called adaptive radiation.”