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: x can finish a work in 20 days . y can finish the same work in 15 days . yworked for 9 days and left the job . how many days does x alone need to finish the remaining work ? 
Options: a ) 3 , b ) 5 , c ) 6 , d ) 8 , e ) 9
Example Output: d

Example 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
Example Output: c

Example Input: Problem: 24 people can write 48 book in 6 days working 8 hour a day . then in how many day 192 can be written by 50 people ? 
Options: a ) 223 / 26 , b ) 288 / 27 , c ) 309 / 22 , d ) 288 / 26 , e ) 288 / 25
Example Output:
e