4.1.4[in fact], the best educated guess（最有根据的推测） (we can make)， [using the little (that we do know about the conditions for carbon-based life(碳基生命)) ], leads us to estimate that perhaps one in 100,000 stars （恒星） might have a life-bearing planet （孕育生命的行星）(orbiting it).The attributive clause “that we do know about the conditions for carbon-based life”is used to modify the antecedent of ( ).

A. using
B. guess
C. we
D. the little (information)