In context, which version of sentence 5 (reproduced below) provides the most effective explanation of the “critical period” mentioned in sentence 4? Such a period also exists for the development of eyesight.

A. (As it is now)

B. This concept applies to the fields of developmental biology and developmental psychology.

C. There are several helpful models of what this important period actually looks like for language acquisition.

D. It was first developed by early educators such as Dr. Maria Montessori, though she referred to it as a “sensitive period.”

E. It designates the time in one’s life during which the capacity to absorb the rules and structure of a language is maximized.