Excavations Between Bed I and Bed II at Olduvai Suggest

Excavations between Bed I and Bed II at Olduvai suggest that significant changes in technology occurred during a comparatively short 200,000-year period. The tools found illustrate a shift toward functional differentiation, which means that

A) there was a broadening of the range of staples in diet, despite the fact that the tools remained unchanged.
B) some tools were used for utilitarian purposes, whereas others served ritualistic purposes.
C) males used heavier tools, and females, lighter ones.
D) the tools were being made and used for different jobs, such as smashing bones or digging for tubers.
E) the same tools were being used more creatively for a variety of uses.