Select the letter-cluster that can replace the question mark (?) in the following series.AR, CP, ?, GL, IJ, KH

Select the letter-cluster that can replace the question mark (?) in th

1.	Select the letter-cluster that can replace the question mark (?) in the following series.AR, CP, ?, GL, IJ, KH
A.	DN
B.	EN
C.	EM
D.	DM
Answer» C. EM