In the following question, which one set of numbers when sequentially placed at the gaps in the given number series shall complete it?1 2 _ 1 _ 2 2 1 _ 2 _ 1

In the following question, which one set of numbers when sequentially

1.	In the following question, which one set of numbers when sequentially placed at the gaps in the given number series shall complete it?1 2 _ 1 _ 2 2 1 _ 2 _ 1
A.	2122
B.	1221
C.	2112
D.	1211
Answer» D. 1211