There are $15$ people coming to Laura's party.  Laura wants to prepare four meatballs, two slices of pizza, and three scoops of ice cream for each guest.  A bag (B) of meatballs contains $12$ meatballs, a pizza (P) can be cut up into $10$ slices and a tub (T) of ice cream can be divided into $5$ scoops.  Which expression shows how many bags of meatballs, pizzas and tubs of ice cream Laura must buy? 
选项为:A:$3\rm B+5\rm P+9\rm T$  B:$3\rm B+5\rm P+4\rm T$  C:$9\rm B+3\rm P+5\rm T$  D:$15\rm B+6\rm P+3\rm T$  E:$5\rm B+3\rm P+9\rm T$  请回答其中一个选项.