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'.

Ex Input:
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

Ex Output:
c


Ex Input:
Problem: in what time will a train 140 meters long cross an electric pole , if its speed is 210 km / hr 
Options: a ) 5 seconds , b ) 4.5 seconds , c ) 3 seconds , d ) 2.4 seconds , e ) none of these

Ex Output:
d


Ex Input:
Problem: the speed of a boat in still water in 42 km / hr and the rate of current is 8 km / hr . the distance travelled downstream in 44 minutes is : 
Options: a ) 86.6 km , b ) 46.6 km , c ) 36.6 km , d ) 35.6 km , e ) 26.6 km

Ex Output:

c