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: ajay can ride 50 km in 1 hour . in how many hours he can ride 1250 km ? 
Options: a ) 10 hrs , b ) 15 hrs , c ) 20 hrs , d ) 25 hrs , e ) 18 hrs
Example Output: d

Example Input: Problem: two consultants can type up a report in 12.5 hours and edit it in 7.5 hours . if mary needs 30 hours to type the report and jim needs 12 hours to edit it alone , how many r hours will it take if jim types the report and mary edits it immediately after he is done ? 
Options: a ) 41.4 , b ) 34.1 , c ) 13.4 , d ) 12.4 , e ) 10.8
Example Output: a

Example Input: Problem: if 36 men can do a piece of work in 15 hours , in how many hours will 15 men do it ? 
Options: a ) 22 , b ) 36 , c ) 60 , d ) 88 , e ) 72
Example Output:
b