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: if 4 spiders make 3 webs in 9 days , then how many days are needed for 1 spider to make 1 web ?
Options: a ) 9 , b ) 12 , c ) 27 , d ) 24 , e ) 16
Example Output: b

Example Input: Problem: if the wheel is 21 cm then the number of revolutions to cover a distance of 1056 cm is ?
Options: a ) 8 , b ) 27 , c ) 10 , d ) 7 , e ) 19
Example Output: a

Example Input: Problem: a and b together can complete a piece of work in 10 days . if a alone can complete the same work in 15 days , in how many days , in how many days can b alone complete that work ?
Options: a ) 10 , b ) 30 , c ) 25 , d ) 15 , e ) 45
Example Output:
b