Darwin finches show a variety of beaks suited for eating large seeds, flying insets and cactus seeds but the ancestral stock of darwin finches were :-
Darwin finches show a variety of beaks suited
for eating large seeds, flying insects and cactus seeds but the ancestral stock
of Darwin finches were seed eaters who dwelled on land. To meet their
nutritional and ecological demands in order to survive better, they developed
beaks modified for eating insects, cactus, fruits, etc.
So, the correct answer is 'Seed eater'.