Which of the following is a flightless bird?

Kiwi

The correct answer is Option (3) -Kiwi

The flightless bird among the options provided is the Kiwi.

Kiwi birds are native to New Zealand and are known for their small size, round body shape, and distinctive long beaks. They belong to the family Apterygidae and are flightless, meaning they are unable to fly. Instead, they have adapted to a terrestrial lifestyle, using their strong legs and long beaks to forage for food on the forest floor. Kiwis are nocturnal birds and have evolved unique adaptations to their environment, including a keen sense of smell and specialized feathers that help them navigate in the dark.