In this task, you need to answer the given multiple-choice question on the general math. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Example Input: Problem: it takes 30 days to fill a laboratory dish with bacteria . if the size of the bacteria doubles each day , how long did it take for the bacteria to fill one sixteenth of the dish ? 
Options: a ) 16 days , b ) 26 days , c ) 27 days , d ) 28 days , e ) 29 days
Example Output: b

Example Input: Problem: the average marks of a class of 30 students is 40 and that of another class of 50 students is 60 . find the average marks of all the students ? 
Options: a ) 82.5 , b ) 52.9 , c ) 52.2 , d ) 52.5 , e ) 52.7
Example Output: d

Example Input: Problem: a line that passes through ( – 1 , – 4 ) and ( 4 , k ) has a slope = k . what is the value of k ? 
Options: a ) 3 / 4 , b ) 1 , c ) 4 / 3 , d ) 2 , e ) 7 / 2
Example Output:
b