The process by which certain birds form attachments during a critical period very early in life is called

A) imprinting.
B) conservation.
C) assimilation.
D) accommodation.

Imprinting

A form of rapid learning occurring at a particular life stage, where a young animal forms attachments to a stimulus, often its caregiver.

Birds

Warm-blooded, feathered vertebrates of the class Aves, known for their ability to fly, although some species are flightless.