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: two cars start at the same time from opposite ends of a highway that is 333 miles long . one car is riding at 54 mph and the second car is riding at 57 mph . how long after they begin will they meet ? 
Options: a ) 1 , b ) 2 , c ) 3 , d ) 4 , e ) 5
Example Output: c

Example Input: Problem: a room of 2 m 40 cm long and 4 m 20 cm broad is to be paved with square tiles . find the least number of square tiles required to cover the floor . 
Options: a ) 23 , b ) 25 , c ) 28 , d ) 60 , e ) 240
Example Output:
c