Which of the Following Best Describes the Concept of a Sensitive

Which of the following best describes the concept of a sensitive period for language learning?

A) A time period in which the learning of language must occur or it never will
B) A time period in which the rules of language are best learned
C) A time period in which children must be exposed to spoken language in order to learn it
D) A time period in which the capacity for learning new words is especially pronounced