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: a searchlight on top of the watchtower makes 4 revolutions per minute . what is the probability that a man appearing near the tower will stay in the dark for at least 12 seconds ? 
Options: a ) 1 / 2 , b ) 2 / 3 , c ) 1 / 3 , d ) 1 / 4 , e ) 1 / 5
Example Output: e

Example Input: Problem: x can finish a work in 20 days . y can finish the same work in 15 days . yworked for 9 days and left the job . how many days does x alone need to finish the remaining work ? 
Options: a ) 3 , b ) 5 , c ) 6 , d ) 8 , e ) 9
Example Output: d

Example Input: Problem: in a 1000 m race , a beats b by 200 meters or 25 seconds . find the speed of b ? 
Options: a ) 5 m / s , b ) 8 m / s , c ) 9 m / s , d ) 4 m / s , e ) 2 m / s
Example Output:
b