By "the nature of viruses" the author refers to ______.

A．it leads to results that can be appreciated
B．it provides the basis for scientific progress
C．it is driven out by applied research
D．its results cannot be anticipated

A．devote 7% or so of their budget to basic research
B．devote a large portion of their budget to applied research
C．realize that progress depends on basic research
D．encourage their career scientists to experiment