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: the average of the marks of 30 students in a class is 45 . if the marks of each student are doubled , find the new average ?
Options: a ) 85 , b ) 77 , c ) 33 , d ) 90 , e ) 75
Example Output: d

Example Input: Problem: patrick purchased 60 pencils and sold them at a loss equal to the selling price of 20 pencils . the cost of 60 pencils is how many times the selling price of 60 pencils ?
Options: a ) 0.75 , b ) 0.8 , c ) 1 , d ) 1.33 , e ) 1.75
Example Output: d

Example Input: Problem: a student chose a number , multiplied it by 8 , then subtracted 138 from the result and got 102 . what was the number he chose ?
Options: a ) 30 , b ) 120 , c ) 130 , d ) 140 , e ) 150
Example Output:
a