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: two trains are moving in opposite directions at 60 km / hr and 90 km / hr . their lengths are 1.25 km and 1.00 km respectively . the time taken by the slower train to cross the faster train in seconds is ?
Options: a ) 48 , b ) 9 , c ) 7 , d ) 67 , e ) 54
Example Output: e

Example Input: Problem: an intern wants to label folders with numbers using digit stickers only . if the intern uses 999 stickers , how many folders have been numbered ? ( the numbers of the folders are consecutive and the number of the first folder is 1 ) .
Options: a ) 287 , b ) 369 , c ) 370 , d ) 371 , e ) 430
Example Output: b

Example Input: Problem: a 1100 m long train crosses a tree in 110 sec , how much time will it take to pass a platform 700 m long ?
Options: a ) 288 , b ) 190 , c ) 188 , d ) 180 , e ) 12
Example Output:
d