There were $$31$$ runners competing in a race. The number of runners who finished before John is $18$ less than the number of runners who finished later than John. At what place did John finish? (Adapted from 1998 Math Kangaroo Problem, Level 3 - 4, Question \#13) 
选项为:A:$$6$$  B:$$7$$  C:$$8$$  D:$$20$$  E:$$21$$  请回答其中一个选项.