Thoreau's attitude toward society can be best characterized as one of ______.

A．It is wrong to overestimate the importance of teaching.
B．Teaching and research are contradictory to each other.
C．Research can never be emphasized too much.
D．The relationship between teaching and research should not be simplified.

A．Distinguished professors at research universities should concentrate on research only.
B．The separation of teaching from research can lower the quality of future scientists.
C．It is of utmost importance to improve teaching in elementary schools in order to train new scientists.
D．The rapid development of modem science makes it impossible to combine teaching with re search.