The answer is C. Cuckoo.
A crane, flamingo, curlew, and duck are all birds. A cuckoo is a bird that lays its eggs in the nests of other birds.
Cranes are large, long-legged birds that live in wetlands and open grasslands. They have long necks and legs, and their bodies are covered in feathers. Cranes are migratory birds, which means they travel long distances to find food and breeding grounds.
Flamingos are tall, long-legged birds with long necks and bills. They are pink or red in color, and they live in wetlands and shallow lakes. Flamingos eat mostly algae and small invertebrates.
Curlews are long-legged wading birds with long, down-curved bills. They have brown or gray plumage, and they live in open grasslands, wetlands, and coastal areas. Curlews eat insects, worms, and other small invertebrates.
Ducks are waterfowl that live in both fresh and saltwater. They have short legs and webbed feet, and their bodies are covered in feathers. Ducks are mostly migratory birds, but some species live year-round in temperate climates. Ducks eat a variety of food, including plants, insects, and small fish.