Hint: It is possible to classify the Darwin finches or Geospiza magnirostris into three groups of finch species. They are located on the Islands of the Galapagos. These finches have adapted to new niches due to the absence of other species of birds and have shown differences between them. The beaks and bodies of the finches underwent many modifications that allowed them to eat certain types of foods such as nuts, fruits, and insects.
Complete answer: The small black birds present in the Galapagos Islands, later known as Darwin's finches, were primarily adapted to seed-eating characteristics. Many other forms formed out of these birds that had an altered beak. The improvement in their beaks was largely due to their habit of feeding. This has converted them into vegetarian and insectivorous finches. But there were no species of finch to feed on carrion or rotting dead matter seen or reported.
Originally, the small black birds found on the Galapagos Islands, which later became known as Darwin's finches, were adapted to seed-eating characteristics. Depending on the food habit, several other forms developed from these with altered beaks. This made them capable of being insectivorous and vegetarian finches.
So, option E-seed eating is the right answer.
Note: The finches vary according to their eating habits. Through their crushing beaks, the ground finches consume ticks. The sharp-beaked field finch hops on the backs of masked boobies and red-footed boobies pecking at their flesh and feeding on their blood, also known as the "vampire finch". Some other kinds of finches, such as woodpecker and mangrove finches, use tiny twigs or cactus spines as an instrument to dine on the larvae stored in tree branches.