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 Q]: Problem: 8597 - ? = 7429 - 4358 
Options: a ) 3567 , b ) 6424 , c ) 6835 , d ) 5526 , e ) none of these
[EX A]: d

[EX Q]: Problem: if n is an integer , f ( n ) = f ( n - 1 ) - n and f ( 4 ) = 14 . what is the value of f ( 6 ) ? 
Options: a ) 3 , b ) 0 , c ) 1 , d ) 2 , e ) 4
[EX A]: a

[EX Q]: Problem: andy solves problems 74 to 135 inclusive in a math exercise . how many problems does he solve ? 
Options: a ) 53 , b ) 62 , c ) 51 , d ) 50 , e ) 49
[EX A]:
b