A construction team is going to build a road of $50$ miles. The plan is that it finishes $30$\% of the road in the first month, $40$\% of the road in the second month and $30$\% of the road in the third month. How many miles can be built after two months? 
选项为:A:$$15$$  B:$$20$$  C:$$30$$  D:$$35$$  请回答其中一个选项.