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 train 441 m long can cross an electric pole in 21 sec and then find the speed of the train ? 
Options: a ) 88 kmph , b ) 89 kmph , c ) 76 kmph , d ) 16 kmph , e ) 18 kmph
Example Output: c

Example Input: Problem: convert 0.35 in to a vulgar fraction ? 
Options: a ) 18 / 50 , b ) 16 / 50 , c ) 7 / 20 , d ) 19 / 50 , e ) none
Example Output: c

Example Input: Problem: a and b go around a circular track of length 300 m on a cycle at speeds of 18 kmph and 54 kmph . after how much time will they meet for the first time at the starting point ? 
Options: a ) 120 sec , b ) 198 sec , c ) 60 sec , d ) 665 sec , e ) 276 sec
Example Output:
c