Question

Which is a flightless bird?
(A) Albatross
(B) Emu
(C) Crane
(D) Flamingo

Answer 1

Birds belonged to the class Aves and the kingdom Animalia. These are the warm-blooded vertebrates which are the only organism that can fly. They have feathers, beaks and the four chambered hearts. They possess air chambers in their body, this helps them to fly.

Complete answer:
Some birds lost their ability to fly through the process of evolution. These birds are also called the flightless birds.
Of the given options
(A) Albatross:-These are the large sea birds widely seen in the regions of the Southern Ocean and the North Pacific Ocean. They have the longest wingspan which is up to eleven feet. It is found that these birds can travel $10,000$ miles in a single flight.
(B) Emu:-These birds are specified as Dromaius novaehollandiae. It is the second largest bird living today. They are tall up to $2$ meters. These are the flightless birds with the small wings.
(C) Crane:-These birds possess long necks and long legs. They are similar to herons. They can fly and live predominantly in the regions of North America.
(D) Flamingo:-These birds are widespread in most of the areas. They have the longest lifespan of about $83$ years. They have the ability to fly $600\,Km$ in one night.

Thus, the correct answer is option (B)

Note: An example for the flightless bird is penguin, Ostrich, emu, cassowaries, rhea, elephant birds, water fowls, pelicans, kiwi etc. Among these birds, the island rail is the smallest flightless bird and the ostrich is the largest flightless bird.