In this task, you need to answer the given multiple-choice question on the physics. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

[Q]: Problem: the curved surface of a sphere is 64 cm 2 . find its radius ?
Options: ['a ) 8', 'b ) 3', 'c ) 4', 'd ) 9', 'e ) 7']
[A]: c

[Q]: Problem: 30 buckets of water fill a tank when the capacity of each bucket is 13.5 litres . how many buckets will be required to fill the same tank if the capacity of each bucket is 9 litres ?
Options: a ) 30 , b ) 32 , c ) 45 , d ) data inadequate , e ) none of these
[A]: c

[Q]: Problem: a man can row 7 a kmph in still water . if in a river running at 1.5 km / hr an hour , it takes him 50 minutes to row to a place and back , how far off is the place ?
Options: a ) 4 km , b ) 2 km , c ) 5 km , d ) 3 km , e ) 1 km
[A]:
d