Correct Answer - Option 4 : FHQSLTVOQ
In the first pair:
VIDEO : UWHJWDFNP
Each letter on the left side of the colon is replaced by its predecessor and successor as per the English alphabetical series.
For example, U is the predecessor of V and W is the successor of V. Thus, UW will replace V to form the word on the right side of the colon.
Similarly, the predecessor and successor of the word GROUP are:
G → FH
R → QS
O → L
U → TV
P → OQ
Hence, FHQSLTVOQ will come in place of the blank.