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: the sum of two consecutive integers is 15 . find the numbers . 
Options: a ) 17 , 18 , b ) 7 , 8 , c ) 5 , 6 , d ) 1 , 2 , e ) 8 , 9

Ex Output:
b


Ex Input:
Problem: what is the least number of square tiles required to pave the floor of a room 11 m 50 cm long and 1 m 50 cm broad ? 
Options: a ) 724 , b ) 804 , c ) 69 , d ) 844 , e ) none

Ex Output:
c


Ex Input:
Problem: a train running at the speed of 36 km / hr crosses a pole in 9 seconds . find the length of the train ? 
Options: a ) 150 meter , b ) 299 meter , c ) 666 meter , d ) 90 meter , e ) 144 meter

Ex Output:

d