The correct answer is: a) Khasi.
Khasi is a tonal language spoken by the Khasi people of Meghalaya, India. It is one of the three major languages spoken in Meghalaya, along with Garo and War. Khasi is a tonal language, which means that the pitch of a word can change its meaning. There are three tones in Khasi: high, low, and rising.
Garo is a language spoken by the Garo people of Meghalaya, India. It is one of the three major languages spoken in Meghalaya, along with Khasi and War. Garo is not a tonal language. The pitch of a word in Garo does not change its meaning.
War is a language spoken by the War people of Meghalaya, India. It is one of the three major languages spoken in Meghalaya, along with Khasi and Garo. War is not a tonal language. The pitch of a word in War does not change its meaning.
Lyngngam is a language spoken by the Lyngngam people of Meghalaya, India. It is a minor language spoken by a small number of people. Lyngngam is not a tonal language. The pitch of a word in Lyngngam does not change its meaning.