What type of bird has a specialized beak for eating insects?

a. hawk

b. buzzard

c. falcon

d. robin

You can simply figure this out through the process of elimination.

Hawk's, buzzard's and falcon's all are carnivores, eating snakes and similar small animals, however a Robin feeds on insects because of its small size.

Knowing this you can rule out A, B and C and thus the answer being D, robin.