Jack, Sarah, and Jimmy participated in a maths competition.  Jack says: "I won the competition."  Sarah says: "I didn\textquotesingle t win the competition."  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.