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'.

Ex Input:
Problem: if ( a – b ) is 9 more than ( c + d ) and ( a + b ) is 3 less than ( c – d ) , then ( a – c ) is : 
Options: a ) 6 , b ) 2 , c ) 3 , d ) 4 , e ) 5

Ex Output:
c


Ex Input:
Problem: if 5 x = 6 y and xy ≠ 0 , what is the ratio of 1 / 3 * x to 1 / 5 * y ? 
Options: a ) 25 / 6 , b ) 36 / 25 , c ) 2 , d ) 5 / 6 , e ) 25 / 36

Ex Output:
c


Ex Input:
Problem: carrie likes to buy t - shirts at the local clothing store . they cost $ 8.75 each . one day , she bought 18 t - shirts . how much money did she spend ? 
Options: a ) $ 150 , b ) $ 70 , c ) $ 200 , d ) $ 171.6 , e ) $ 190

Ex Output:

b