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'.

[Q]: Problem: if a - b = 5 and a 2 + b 2 = 31 , find the value of ab . 
Options: a ) 9 , b ) 2 , c ) 3 , d ) 7 , e ) 12
[A]: c


[Q]: Problem: 25.25 / 2000 is equal to : 
Options: a ) 1.012526 , b ) 0.012625 , c ) 0.12526 , d ) 0.12625 , e ) 0.12725
[A]: b


[Q]: Problem: if in a certain code ` ` range ' ' is coded as 12345 and ` ` random ' ' is coded as 123678 . then the code for the word ` ` gone ' ' would be 
Options: a ) 3569 , b ) 1552 , c ) 4573 , d ) 4735 , e ) 5235
[A]:
d