Explanation:

Angle of arc of minute hand is asked
total time gap: 90 min 
for 60 min--minute hand covers 360
for 60+ min----it will be reset and starts from 0 again
for 30 min---it covers 180
so for 90min = 60 min + 30 min = 0+180 = 180

Hence, option 3 is the correct answer.