Which letter-cluster will replace the question mark (?) to complete the given series?

ABCD, FVJV, KPQN, PJXF, ?

Which letter-cluster will replace the question mark (?) to complete the given series?

QRM, PWD, OBU, NGL, ?

Which letter-cluster will replace the question mark (?) to complete the given series?
 ZFOE, PYUA, FRAW, VKES, ?

Which letter-cluster will replace the question mark (?) to complete the given series?
 ERKV, HYVK, ?, NMRO, QTCD

Which letter-cluster will replace the question mark (?) to complete the given series?
 TBNF, CJUL, LRBR, UZIX, ?

Which letter-cluster will replace the question mark (?) to complete the given series?

RLV, PNS, NPP, ?, JTJ

Which letter-cluster will replace the question mark (?) to complete the given series?

ACFD, CFHG, ?, GLLM, IONP

Select the combination of letters that when sequentially placed in the blanks of the given series will complete the series.
 A B Z _ P A B _ K P A B X K _ A B _ K P