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 14 men do a work in 80 days , in how many days will 20 men do it ? 
Options: a ) 18 days , b ) 38 days , c ) 42 days , d ) 48 days , e ) 56 days
Example Output: e

Example Input: Problem: a train is 410 meter long is running at a speed of 45 km / hour . in what time will it pass a bridge of 140 meter length 
Options: a ) 20 seconds , b ) 44 seconds , c ) 40 seconds , d ) 50 seconds , e ) none of these
Example Output: b

Example Input: Problem: a man can row 6 kmph in still water . when the river is running at 1.2 kmph , it takes him 1 hour to row to a place and back . what is the total distance traveled by the man ? 
Options: a ) 7.76 kms , b ) 8.76 kms , c ) 5.76 kms , d ) 3.76 kms , e ) 4.76 kms
Example Output:
c