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 250 m long running at 72 kmph crosses a platform in 15 sec . what is the length of the platform ? 
Options: a ) 50 m , b ) 200 m , c ) 250 m , d ) 270 m , e ) 300 m

Ex Output:
a


Ex Input:
Problem: a can do a work in 8 days . b can do the same work in 16 days . if both a & b are working together in how many days they will finish the work ? 
Options: a ) 3 days , b ) 16 / 3 days , c ) 3 / 4 days , d ) 9 / 12 days , e ) 5 / 7 days

Ex Output:
b


Ex Input:
Problem: car x began traveling at an average speed of 35 miles per hour . after 72 minutes , car y began traveling at an average speed of 42 miles per hour . when both cars had traveled the same distance , both cars stopped . how many miles did car x travel from the time car y began traveling until both cars stopped ? 
Options: a ) 105 , b ) 140 , c ) 175 , d ) 210 , e ) 245

Ex Output:

d