In this task, you need to answer the given multiple-choice question on geometry. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

[Q]: Problem: the length of a rectangle is halved while its width is also halved . what is the % change in area ? 
Options: a ) 25 % , b ) 30 % , c ) 50 % , d ) 65 % , e ) 75 %
[A]: e


[Q]: Problem: if the length of the longest chord of a certain circle is 10 , what is the radius of that certain circle ? 
Options: ['a ) 2.5', 'b ) 5', 'c ) 10', 'd ) 15', 'e ) 20']
[A]: b


[Q]: Problem: right triangle abc is to be drawn in the xy - plane so that the right angle is at a and ab is parallel to the y - axis . if the x - and y - coordinates of a , b , and c are to be integers that are consistent with the inequalities - 7 ≤ x ≤ 1 and 4 ≤ y ≤ 9 , then how many different triangles can be drawn that will meet these conditions ? 
Options: a ) 54 , b ) 432 , c ) 2,160 , d ) 3024 , e ) 148,824
[A]:
d