Which letter-cluster will replace the question mark (?) to complete the given series?
DKLX, EMOU, FORR, ?, HSXL
1
GQTP
2
GQUP
3
GQUO
4
GQTO
Which letter-cluster will replace the question mark (?) to complete the given series?
DKLX, EMOU, FORR, ?, HSXL