The word “it” in paragraph 3 refers to __________.

A. the act of humming

B. the Pirahã’s language

C. the Pirahã tribe

D. the language of males

Dẫn chứng “Their language, he found, was not just simple grammatically; it was restricted in its range of sounds and differed between the sexes. For the men, it has just eight consonants and three vowels…”