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: in a 80 meters race a beats b by 56 m or 7 seconds . a ' s time over the course is : 
Options: a ) 3 seconds , b ) 12 seconds , c ) 10 seconds , d ) 18 seconds , e ) 28 seconds

Ex Output:
a


Ex Input:
Problem: two trains are moving in the same direction at 72 kmph and 36 kmph . the faster train crosses a man in the slower train in 20 seconds . find the length of the faster train ? 
Options: a ) 270 , b ) 277 , c ) 200 , d ) 257 , e ) 271

Ex Output:
c


Ex Input:
Problem: 65 boys can complete a work in 30 days . how many men need to complete twice the work in 20 days 
Options: a ) 160 , b ) 170 , c ) 180 , d ) 195 , e ) 200

Ex Output:

d