Which one set of letters when sequentially placed at the gapes in the given letters series shall complete it ?

BR _ _ NB _ O _ NB

The logic followed here is:

Given Sequence: BR _ _ NB _ O _ NB

Now, putting the letters in the blank spaces given in the option one by one:

Option 1) WNWN → BR W N NB W O N NB → False

Option 2) OWRW → BR O W NB R O W NB → True

Option 3) OWOW → BR O W NB O O W NB → False

Option 4) RORO → BR R O NB R O O NB → False

Here, 'Option 2' followed a pattern. Hence, the correct answer is "Option 2".