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'.

Ex Input:
Problem: a cube of side two meter length is cut into small cubes of side 10 cm each . how many such small cubes can be obtained ? 
Options: a ) 2878 , b ) 2778 , c ) 1000 , d ) 8000 , e ) 8900

Ex Output:
d


Ex Input:
Problem: there are 17 stations between hyderabad and bangalore . how many second class tickets have to be printed , so that a passenger can travel from any station to any other station ? 
Options: a ) 156 , b ) 167 , c ) 157 , d ) 342 , e ) 380

Ex Output:
d


Ex Input:
Problem: if a light flashes every 6 seconds , how many times will it flash in 1 / 5 of an hour ? 
Options: a ) 81 , b ) 101 , c ) 121 , d ) 141 , e ) 161

Ex Output:

c