The apartment complex consisted of individual buildings , with apartments which were accessed from inside a common entry way . I pulled my bike in , placed it by the door , and went into the apartment to make a phone call . When I returned ( less than a few minutes later ) , the bike was gone .
According to the above context, choose the best option to answer the following question.
Question: Why was the bike stolen ?
Options:
A. The narrator left it on the grass .
B. The thief knew the lock combination .
C. It was left unlocked by the narrator .
D. None of the above choices .


C