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.

WITNESS : SSENTIW :: SILENCE : ECNELIS :: PROTECT : ?

TCETORP

Logic here is :

Letters on right side are in reverse order of letters on left side .

As seen in following series :

WITNESS : SSENTIW

WITNESS :- in reverse order = SSENTIW

&  SILENCE : ECNELIS 

  SILENCE :- in reverse order = ECNELIS 

Similarly ,

PROTECT : ?

Reverse order of PROTECT = TCETORP

TCETORP is correct answer .