A teacher believes that students must be given a plenty of comprehensible input as it will facilitate the acquisition of language. This belief of the teacher is related to :

Correct option is D

Stephen Krashen’s theory of language acquisition.
Stephen Krashen's theory of language acquisition is based on the idea that language is acquired through comprehensible input. Comprehensible input is input that is slightly above the learner's current level of understanding. By providing students with a lot of comprehensible input, teachers can help them to acquire language naturally and without conscious effort.