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'.

Example Input: Problem: if a tire rotates at 400 revolutions per minute when the car is traveling 72 km / h , what is the circumference of the tire ? 
Options: a ) 7 meters , b ) 9 meters , c ) 8 meters , d ) 5 meters , e ) 3 meters
Example Output: e

Example Input: Problem: a can do a work in 4 days . b can do the same work in 6 days . both a & b together will finish the work and they got $ 1000 from that work . find their shares ? 
Options: a ) 600,400 , b ) 500,500 , c ) 300,700 , d ) 800,200 , e ) 550,450
Example Output: a

Example Input: Problem: a train 100 meters long completely crosses a 300 meters long bridge in 30 seconds . what is the speed of the train is ? 
Options: a ) 32 kmph , b ) 48 kmph , c ) 34 kmph , d ) 43 kmph , e ) 40 kmph
Example Output:
b