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: if a and b are the roots of the equation x 2 - 9 x + 20 = 0 , find the value of a 2 + b 2 + ab ? 
Options: a ) 57 , b ) 59 , c ) 61 , d ) 63 , e ) 65
Example Output: c

Example Input: Problem: 1 , 3,5 , 7,9 , . . 50 find term of sequnce for this . 
Options: a ) 1356 , b ) 1557 , c ) 1688 , d ) 1700 , e ) 2500
Example Output: e

Example Input: Problem: farm tax is levied on the 50 % of the cultivated land . the tax department collected total $ 3840 through the farm tax from the village of mr . willam . mr . willam paid only $ 480 as farm tax . the percentage of total land of mr . willam over the total taxable land of the village is : 
Options: a ) 15 % , b ) 25 % , c ) 0.125 % , d ) 0.2083 % , e ) none
Example Output:
b