What Can Be Said About Sensitive Windows for Language Acquisition

What can be said about sensitive windows for language acquisition?

A) Children do not start to acquire any language before the age of 1 year.
B) People can learn to speak languages equally well, regardless of the age of acquisition.
C) Some aspects of language, such as accents, do not show any evidence for sensitive windows for acquisition.
D) People who are raised bilingually have two distinct language centers in their brain that do not overlap.
E) Learning a sign language is subject to a sensitive window constraint similar to that when learning a spoken language.