Dean swims for $72$ minutes. To keep his mind active, he works out what fraction of the total time has passed at each half minute and minute from the start. How many of the results of his calculations can be expressed in the form $\frac{1}{n}$, where $n$ is an integer greater than $1$? 
选项为:A:$$12$$  B:$$13$$  C:$$14$$  D:$$15$$  E:$$16$$  请回答其中一个选项.