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: what is the maximum number of pieces of birthday cake of size 2 ” by 2 ” that can be cut from a cake 20 ” by 20 ” ? 
Options: a ) 5 , b ) 100 , c ) 16 , d ) 20 , e ) 25
Example Output: b

Example Input: Problem: mahesh can do a piece of work in 35 days . he works at it for 20 days and then rajesh finished it in 30 days . how long will y take to complete the work ? 
Options: a ) 45 , b ) 25 , c ) 37 , d ) 41 , e ) 70
Example Output: e

Example Input: Problem: a person travels equal distances with speeds of 3 km / hr , 4 km / hr and 5 km / hr and takes a total time of 47 minutes . the total distance ( in km ) is : 
Options: a ) 1 , b ) 2 , c ) 3 , d ) 4 , e ) 5
Example Output:
c