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: two taps a and b can fill a cistern in 12 minutes and 18 minutes respectively . they are turned on at the same time . if the tap a is turned off after 4 minutes , how long will tap b take to fill the rest of the cistern ? 
Options: a ) 8 min . , b ) 9 min . , c ) 10 min . , d ) 7 min . , e ) none of these

Ex Output:
a


Ex Input:
Problem: if the wheel is 14 cm then the number of revolutions to cover a distance of 3520 cm is ? 
Options: a ) 22 , b ) 28 , c ) 17 , d ) 12 , e ) 40

Ex Output:
e


Ex Input:
Problem: one men and three women working 7 hours a day finish a work in 5 days . four men and four women working 3 hours a day complete the work in 7 days . the number of days in which only 7 men working 4 hours a day will finish the work is ? 
Options: a ) 4 days , b ) 5 days , c ) 6 days , d ) 7 days , e ) 8 days

Ex Output:

b