David and Billy are on the bus together. They sit in the same column. There are $5$ people in front of David, Billy is in the middle. There are $10$ people behind Billy, and David is in the middle. How many people in this column? (adapted from2004 Math Kangaroo Problem, Level 3 - 4, Question \#19) 
选项为:A:$$14$$  B:$$13$$  C:$$12$$  D:$$11$$  E:$$10$$  请回答其中一个选项.