When Compared to Humans in Their Language Ability, the Most

When compared to humans in their language ability, the most linguistically talented apes ________.

A) acquire signs faster than the sequence in which humans do
B) achieve a level of language learning that is equivalent to that of a human teenager in terms of vocabulary
C) un­derstand and consistently use correct word order (syntax)
D) seldom prog­ress beyond two- or three-word combinations