The owner of a bicycle store had a sale on bicycles(two-wheelers) and tricycles(three-wheelers). Each cycle had two pedals. When he counted the total number of pedals of the cycles, he got 50 . When he counted the total number of wheels of the cycles, he got 64 . How many tricycles were offered in the sale? 
选项为:A:$$8$$  B:$$10$$  C:$$12$$  D:$$14$$  E:$$16$$  请回答其中一个选项.