According to the passage, when had historical archaeologists been trained as anthropologists

A．Why historical archaeology was first developed.
B．How the methods and purpose of historical archaeology have changed.
C．The contributions architects make to historical archaeology.
D．The attitude of professional archaeologists toward historical archaeology.

A．Investigating the recent past.
B．Studying prehistoric cultures.
C．Excavating ancient sites in what is now the United States.
D．Comparing findings made in North America and in Europe.