A.While ,不填
while(=Although)引导让步状语从句； the way作先行词时后面的定语从句由that/ in which引导;或者省略that/ in which后面的定语从句为什么要用in which 而不是which呢看一看the way___you solve the problem 中，the way 作solve的状语，应该是solve sth in the way .所以是in which 而不是which