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 can do a piece of work in 12 days . he worked for 15 days and then b completed the remaining work in 10 days . both of them together will finish it in . 
Options: a ) 12 1 / 2 days , b ) 10 1 / 2 days , c ) 12 1 / 3 days , d ) 10 1 / 3 days , e ) 11 1 / 2 days
Example Output: a

Example Input: Problem: a boat takes 19 hours for travelling downstream fro poin a to point b and coming back to a point c midway between a and b . if the velocity of the stream is 4 kmph and the speed of the boat in still water is 14 kmph , what is the distance between a and b ? 
Options: a ) 180 km , b ) 190 km , c ) 220 km , d ) 230 km , e ) none
Example Output: a

Example Input: Problem: a is twice as good a workman as b and together they complete a work in 12 days . in how many days a alone can do the work ? 
Options: a ) 32 , b ) 33 , c ) 34 , d ) 35 , e ) 36
Example Output:
e