According to the passage, heat from Mount Rainier's summit craters rises from ______.

A．Social science is unified.
B．Social science is a newborn science.
C．What is social science.
D．Specialization in social science is not good.

A．social science is a united science, and cannot be divided into subfields
B．social science may be further divided into smaller parts as the amount of knowledge and information expanding
C．there may be a Renaissance Man in the future
D．the best way to deal with the expansion of information is to know everything