When changing lanes, a driver should use his turning signal to let other drivers know_____ .

题目：When changing lanes, a driver should use his turning signal to let other drivers know_____ .

A. he is entering which lane
B. which lane he is entering
C. is he entering which lane
D. which lane is he entering

喵查答案：B

which引导的句子做know的宾语，句子用陈述语序。