Select the option that represents the letters that, when placed from left to right in the following blanks, will complete the letter-series.

G _ A R E G L _ R _ G _ C _ E G L _ _ E

Select the option that is related to the fifth letter-cluster in the same way as the second letter-cluster is related to the first letter-cluster and the fourth letter-cluster is related to the third letter-cluster.

BET : UXM :: SYP : LRI :: HOX : ?

Select the option that is related to the fifth letter-cluster in the same way as the second letter-cluster is related to the first letter-cluster and the fourth letter-cluster is related to the third letter cluster.

MAGNET : AMNGTE :: FAMILY : AFIMYL :: BLOCKS : ?

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

GTCL, KWEM, OZGN, SCIO, ?