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: in country x a returning tourist may import goods with a total value of $ 500 or less tax free , but must pay an 8 percent tax on the portion of the total value in excess of $ 500 . what tax must be paid by a returning tourist who imports goods with a total value of $ 730 ? 
Options: a ) $ 58.40 , b ) $ 40 . 00 , c ) $ 24.60 , d ) $ 18.40 , e ) $ 16.00
Example Output: d

Example Input: Problem: what is the greatest value of positive integer x such that 2 ^ x is a factor of 100 ^ 50 ? 
Options: a ) 70 , b ) 80 , c ) 90 , d ) 100 , e ) 120
Example Output: d

Example Input: Problem: 117 x 217 + 83 x 83 = ? 
Options: a ) 79698 , b ) 20578 , c ) 80698 , d ) 81268 , e ) none of them
Example Output:
b