【单选题】What is the main idea of the second paragraph?
A.
Over 6000 languages and major dialects are spoken in the world today.
B.
As some languages grow, others disappear.
C.
Languages that grow also develop and change due to class, profession, age group, and other social forces.
D.
Anthropologists are trying to record and preserve ancient languages that are still spoken in remote areas or by the last remaining people in a culture.