Main focus of two main branches of archaeology?

Archeology is the study of past and present human societies. It is both a science and a humanities discipline since it employs scientific methodology to retrieve artifacts and the humanities to study human culture.

The most important aspect of archeology is studying pre-historic, primitive societies since since there are no written records for historians to study. And prehistoric societies comprise 99% of total human history.

There are 5 sub-disciplines (not 2 in A:

Historical Ethnoarcheology Experimental Archeometry Cultural Resources Management