Answer:
A. Study past human societies, focusing mostly on their material remains
Explanation:
Archaeologists help understand the human societies that once existed.
The only way they can do this, is by analyzing the remains of the materials that existed from those periods or times. Proper analysis can give them a clear view of the history if human activities around a particular place.
The option A bests suits the functions of archaeologists.
The option B does not fit in because archaeologists do not focus primarily on the study of language change, rather everything about the society ranging from religion, to politics and to military system.
The option C is too shabby compared to A, as archaeologists are not just treasure collectors. They are researchers who collect the items for study purposes. Most times, the items collected end up in labs not museums.
The option D does not fit in because Archaeologists do not study primate evolution, rather, human societies
