What is the next number in this sequence, 1, 11, 21, 1211, 111221 , 312211 ?	Choose the correct choice from the following answers
A) 1332123 B) 1112321 C) 2221313 D) 1311222 E) 3321233
D   Next in sequence is 13112221.   This series describes each number that came before it:   1 [One]   11 [One One]   21 [Two One(s)]   1211 [One Two and One One(s)]   111221 [One One, One Two, and Two One(s)]   312211 [Three One(s), Two Two(s), and One One]   The next number in the series is:   13112221 [One Three, One One, Two Two(s), Two One(s)]
<result>D</result>
What is the next number in this sequence, 1, 11, 21, 1211, 111221 , 312211 ?