In each of the following questions, various terms of an alphabet series are given with one or more terms missing as shown by (?). Choose the missing terms out of the given alternatives.

11. 

A, B, B, D, C, F, D; H, E, ?, ?

A. E, F
B. F, G
C. F, I
D. J, F
E. J, K

12. 

Z, X, S, I, R, R, ?, ?

A. G,I
B. J, I
C. J,K
D. K,M

13. 

AYBZC, DWEXF, GUHVI, JSKTL, ?

A. MQORN
B. MQNRO
C. NQMOR
D. QMONR

14. 

T, R, P, N, L, ?, ?

A. J, G
B. J, H
C. K, H
D. K, I

15. 

PMT, OOS, NQR, MSQ, ?

A. LUP
B. LVP
C. LVR
D. LWP