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

[EX Q]: Problem: the length of a rectangle is four times its width . if the area is 100 m 2 what is the length of the rectangle ? 
Options: a ) 50 m , b ) 40 m , c ) 80 m , d ) 20 m , e ) 70 m
[EX A]: d

[EX Q]: Problem: the length of a rectangle is reduced by 15 % . by what % would the width have to be increased to maintain the original area ? 
Options: ['a ) 10 %', 'b ) 20 %', 'c ) 17.6 %', 'd ) 30 %', 'e ) 35 %']
[EX A]: c

[EX Q]: Problem: a box measuring 49 inches long by 42 inches wide by 14 inches deep is to be filled entirely with identical cubes . no space is to be left unfilled . what is the smallest number of cubes that can accomplish this objective ? 
Options: a ) 78 , b ) 82 , c ) 84 , d ) 86 , e ) 88
[EX A]:
c