After the final exam results came out, four students wanted to compare who had done best. Who had the best grades?~(adapted from $$2007$$ Math kangaroo Problems, Level $$1-2$$, Question \#$$4$$)  Alice：$12+8$  Bob：$7+9$  Alan：$14+5$~  Tom：$6+8$  Susan: $6+15$ 
选项为:A:Alice  B:Bob  C:Alan  D:Tom  E:Susan  请回答其中一个选项.