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: two trains of length 100 meters and 200 meters are 840 meters apart . they are moving towards each other on parallel tracks , at speeds of 54 km / h and 72 km / h . after how many seconds will the trains meet ? 
Options: a ) 20 , b ) 22 , c ) 24 , d ) 26 , e ) 28
Example Output: c

Example Input: Problem: jose is uploading a file to the internet for a college project . the file weighs 160 megabytes . if jose ' s internet speed for uploading tops 8 megabytes per minute , how long will it take until the upload is completed ? 
Options: a ) 1 hour , b ) 45 minutes , c ) 20 minutes , d ) 5 minutes , e ) 1 hour and 10 minutes
Example Output: c

Example Input: Problem: walking at 5 / 6 of its usual speed , a train is 10 minutes too late . what is usual time to cover the journey ? 
Options: a ) 70 minutes , b ) 2 hours , c ) 2 / 3 hours , d ) 5 / 6 hours , e ) 85 minutes
Example Output:
d