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: a bus 75 m long is running with a speed of 21 km / hr . in what time will it pass a woman who is walking at 3 km / hr in the direction opposite to that in which the bus is going ? 
Options: a ) 5.75 , b ) 7.62 , c ) 11.25 , d ) 4.25 , e ) 3.25

Ex Output:
c


Ex Input:
Problem: a monkey ascends a greased pole 17 metres high . he ascends 2 metres in first minute and slips down 1 metre in the alternate minute . in which minute , he reaches the top ? 
Options: a ) 31 st , b ) 22 nd , c ) 23 rd , d ) 24 th , e ) none of these

Ex Output:
a


Ex Input:
Problem: two pipes a and b can fill a cistern in 10 and 15 minutes respectively . both fill pipes are opened together , but at the end of 3 minutes , ‘ b ’ is turned off . how much time will the cistern take to fill ? 
Options: a ) 6 min , b ) 8 min , c ) 10 min , d ) 12 min , e ) none of these

Ex Output:

b