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: in a 200 meter race a beats b by 35 meters in 7 seconds . a ' s time over the cause is ? 
Options: a ) 47 sec , b ) 40 sec , c ) 45 sec , d ) 33 sec , e ) 35 sec
Example Output: d

Example Input: Problem: a searchlight on top of the watchtower makes 2 revolutions per minute . what is the probability that a man appearing near the tower will stay in the dark for at least 5 seconds ? 
Options: a ) 5 / 6 , b ) 5 / 12 , c ) 7 / 12 , d ) 11 / 12 , e ) 11 / 15
Example Output: a

Example Input: Problem: 15 men can complete a piece of work in 25 days . in how many days can 20 men complete that piece of work ? 
Options: a ) 55 days , b ) 18.75 days , c ) 20 days , d ) 88 days , e ) 44 days
Example Output:
b