Susan participates a Math competition. In round one, she needs to solve $2$ problems. If she works out one problem successfully, she will get $1$ point. Otherwise, she will not lose any points. In round two, she also needs to solve $2$ problems. If she works out one problem successfully, she will get $3$ points. Otherwise, she will lose $1$ point. Which number of points is it impossible for her to have？ 
选项为:A:$$1$$  B:$$3$$  C:$$4$$  D:$$6$$  E:$$7$$  请回答其中一个选项.