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: along a yard 414 metres long , 24 trees are palnted at equal distances , one tree being at each end of the yard . what is the distance between two consecutive trees 
Options: a ) 18 , b ) 19 , c ) 10 , d ) 11 , e ) 12

Ex Output:
a


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: a , band c can do a piece of work in 11 days , 5 days and 55 days respectively , working alone . how soon can the work be done if a is assisted by band c on alternate days ? 
Options: a ) 5 days , b ) 8 days , c ) 9 days , d ) 10 days , e ) 11 days

Ex Output:

a