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 minimum number of square tiles required to tile a floor of length 5 metres 78 cm and width 3 metres 74 cm ? 
Options: a ) 187 , b ) 180 , c ) 190 , d ) 195 , e ) 197
Example Output: a

Example Input: Problem: two trains are approaching each other at 60 mph each . the length of each train is 1 / 6 miles . when the two locomotives ( engines ) meet , how many seconds will it take for them to pass each other completely ? 
Options: a ) 8 sec , b ) 11 sec , c ) 12 sec , d ) 10 sec , e ) 15 sec
Example Output: d

Example Input: Problem: a policeman noticed a criminal from a distance of 240 km . the criminal starts running and the policeman chases him . the criminal and the policeman run at the rate of 8 km and 9 km per hour respectively . what is the distance between them after 3 minutes ? 
Options: a ) 100 m , b ) 120 m , c ) 190 m , d ) 150 m , e ) none of these
Example Output:
c