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: if ( a - b - c + d = 13 ) and ( a + b - c - d = 9 ) , what is the value of ( b - d ) ^ 2 ? 
Options: a ) 4 . , b ) 8 . , c ) 12 . , d ) 16 . , e ) 64 .
[EX A]: a

[EX Q]: Problem: what is the value of 8 1 / 3 % of 600 + 37 ½ of 400 
Options: a ) 100 , b ) 300 , c ) 150 , d ) 200 , e ) 250
[EX A]: d

[EX Q]: Problem: the value of ( 34.5 * 0.473 * 1.567 ) / ( 0.0673 * 23.25 * 7.57 ) is close to 
Options: a ) 2 , b ) 1.15 , c ) 2.05 , d ) 2.16 , e ) 2.35
[EX A]:
d