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: how many halves are there in 9 - fourth ? 
Options: a ) 8 , b ) 4.5 , c ) 3.2 , d ) 7 , e ) 3
Example Output: b

Example Input: Problem: the price of a bushel of corn is currently $ 3.20 , and the price of a peck of wheat is $ 8.80 . the price of corn is increasing at a constant rate of 5 x cents per day while the price of wheat is decreasing at a constant rate of x ( 2 ^ 1 / 2 ) - x cents per day . what is the approximate price when a bushel of corn costs the same amount as a peck of wheat ? 
Options: a ) $ 8.40 , b ) $ 5.10 , c ) $ 5.30 , d ) $ 5.50 , e ) $ 5.60
Example Output: a

Example Input: Problem: if a 2 + b 2 + c 2 = 213 and ab + bc + ca = 6 , then a + b + c is 
Options: a ) 14 , b ) 20 , c ) 15 , d ) 32 , e ) 64
Example Output:
c