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 man can row upstream at 26 kmph and downstream at 30 kmph , and then find the speed of the man in still water ? 
Options: a ) 29 , b ) 28 , c ) 30 , d ) 32 , e ) 23
Example Output: b

Example Input: Problem: a train speeds past a pole in 15 sec and a platform 100 m long in 25 sec , its length is ? 
Options: a ) 158 m , b ) 150 m , c ) 110 m , d ) 130 m , e ) 157 m
Example Output: b

Example Input: Problem: annie and sam set out together on bicycles traveling at 15 and 12 km per hour respectively . after 40 minutes , annie stops to fix a flat tire . if it takes annie 35 minutes to fix the flat tire and sam continues to ride during this time , how many minutes will it take annie to catch up with sam assuming that annie resumes riding at 15 km per hour ? 
Options: a ) 20 , b ) 40 , c ) 60 , d ) 80 , e ) 100
Example Output:
e