Given the question: I'm taking a test and have to guess the right answer to the question after the article. Article: One day, Mr Smith is going to take a train to his hometown. When the train starts, one of his shoes falls to the ground. The train is going faster and faster, and he can't pick it up. Then he quickly takes off the other shoe and throw it on the ground near the fallen shoe. A little boy on the train asks him, "Why do you do that? You have lost one shoe. "Mr Smith answers, " If a man picks them up, he may get a pair of shoes. " Question: What happens to Mr Smith when the train starts? He lost _ . Options: A: his bag B: his watch C: one of his shoes D: nothing
The answer is:
C