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 5 kmph in still water . when the river is running at 2 kmph , it takes him 1 hour to row to a place and black . what is the total distance traveled by the man ? 
Options: a ) 5.75 , b ) 5.7 , c ) 5.76 , d ) 4.2 , e ) 5.71
Example Output: d

Example Input: Problem: if the wheel is 21 cm then the number of revolutions to cover a distance of 1056 cm is ? 
Options: a ) 8 , b ) 27 , c ) 10 , d ) 7 , e ) 19
Example Output: a

Example Input: Problem: 24 men can complete a work in 16 days . 32 women can complete the same work in 24 days . 16 men and 16 women started working and worked for 12 days . how many more men are to be added to complete the remaining work in 2 days ? 
Options: a ) 16 , b ) 24 , c ) 36 , d ) 48 , e ) 49
Example Output:
b