Jack, Sarah, and Jimmy participated in a Maths competition.  \textbf{Jack says: "I won the competition."}  \textbf{Sarah says: "I didn\textquotesingle t win the competition."}  \textbf{Jimmy says: "Jack didn\textquotesingle t win the competition."}  Only one of them told the truth. Who won the Maths competition? 
选项为:A:$$$$Jack  B:Sarah  C:Jimmy  请回答其中一个选项.