Which of the following are true about perceptual constancy?

A. It applies to perception of size and colour only

B. Many visual illusions may be explained by the various constancies

C. Constancies occur in all sensory modalities

D. It keeps the appearance of objects the same inspite of large variations in the initial representation of the stimuli received by the sense organs that are engendered by various environmental factors.

Choose the most appropriate answer from the options given below: