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: some persons can do a piece of work in 8 days . two times the number of these people will do half of that work in ? 
Options: a ) 2 , b ) 4 , c ) 5 , d ) 6 , e ) 8
Example Output: a

Example Input: Problem: a and b together can do a piece of work in 10 days . b alone can finish it in 20 days . in how many days can a alone finish the work ? 
Options: a ) 20 , b ) 10 , c ) 15 , d ) 5 , e ) 7
Example Output: a

Example Input: Problem: water boils at 212 ° f or 100 ° c and ice melts at 32 ° f or 0 ° c . if the temperature of a pot of water is 45 ° c , what is the temperature of the pot of water in ° f ? 
Options: a ) 92 ° f , b ) 97 ° f , c ) 104 ° f , d ) 113 ° f , e ) 118 ° f
Example Output:
d