Correct option is A
Mass density of oil =800kg/m3Acceleration due to gravity g=9.81m/s2Height of oil column =30mMass density of water =1000kg/m3Using Pascal’s Law: Pressure at the same horizontal level is equal.(P)oil=(P)waterρoilghoil=ρwaterghwater800×9.81×30=1000×9.81×h=>h=1000800×30=24m