Correct Answer: VXDZBXF

Solution : Given:
ZXC_BZ_ _VB_XEV_Z_ _VB

To fill the series we have to divide the series – ZXC_B / Z_ _VB / _XEV_ / Z_ _VB
Let's check each option –
First option: UYEZBXF ; ZXC U B / Z YE VB / Z XEV B / Z XF VB (No pattern has been found.)
Second option: UXDZBXF ; ZXC U B / Z XD VB / Z XEV B / Z XF VB (No pattern has been found.)
Third option: VYEZBXG ; ZXC V B / Z YE VB / Z XEV B / Z XG VB (No pattern has been found.)
Fourth option: VXDZBXF ; ZXC V B / Z XD VB / Z XEV B / Z XF VB (The third letter of each part increases by 1; ZXVB is repeated in the series.)

So, the series becomes→ ZXCVBZXDVBZXEVBZXFVB . Hence, the fourth option is correct.