When she was younger, she . . . . . . . . five kilometers a day.

A. had been walking

B. has been walking

C. had walked

D. walked

Answer: Option D

Solution(By Examveda Team)

The sentence is talking about what 'she' used to do when 'she' was 'younger'. 'Had walked' denotes once or a few times therefore 'walked' will be used which will mean regular.