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 train running at the speed of 54 km / hr crosses a pole in 7 seconds . find the length of the train . 
Options: a ) 150 meter , b ) 105 meter , c ) 140 meter , d ) 135 meter , e ) none of these

Ex Output:
b


Ex Input:
Problem: if 8 men or 12 women can do a piece of work in 20 days , in how many days can the same work be done by 6 men and 11 women ? 
Options: a ) 10 days , b ) 11 days , c ) 12 days , d ) 15 days , e ) 17 days

Ex Output:
c


Ex Input:
Problem: a runs twice as fast as b and gives b a start of 64 m . how long should the racecourse be so that a and b might reach in the same time ? 
Options: a ) 75 m . , b ) 128 m . , c ) 150 m . , d ) 100 m . , e ) none of the above

Ex Output:

b