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 , b , k start from the same place and travel in the same direction at speeds of 30 km / hr , 40 km / hr , 80 km / hr respectively . b starts two hours after a . if b and k overtake a at the same instant , how many hours after a did k start ? 
Options: a ) 2 , b ) 3 , c ) 4 , d ) 5 , e ) 6

Ex Output:
d


Ex Input:
Problem: calculate the circumference of a circular field whose radius is 8 centimeters . 
Options: a ) 17 π cm , b ) 18 π cm , c ) 1 π cm , d ) 16 π cm , e ) 6 π cm

Ex Output:
d


Ex Input:
Problem: diana works 10 hours per day on monday , wednesday and friday , and 15 hours per day on tuesday and thursday . she does not work on saturday and sunday . she earns $ 1800 per week . how much does she earn in dollars per hour ? 
Options: a ) 20 , b ) 22 , c ) 30 , d ) 24 , e ) 25

Ex Output:

c