Which Statement About the Limitations of Language Learning in Apes

Which statement about the limitations of language learning in apes is NOT true?

A) Apes' vocabularies are quite small, compared to those of even toddlers.
B) Apes can master words for concrete objects, but have difficulty with abstract concepts.
C) Apes can exhibit an active mastery of a few hundred words but fail to exhibit a passive mastery of them.
D) Ape communication is usually telegraphic; it rarely consists of grammatically correct complex sentences.