Instructions: In this task, you need to answer the given multiple-choice question on geometry. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.
Input: Problem: unit size cubes are stacked inside a big rectangular box having dimensions corresponding to three consecutive multiples of 5 . choose exact number of cubes that can completely fill the box .
Options: ['a ) 750', 'b ) 850', 'c ) 950', 'd ) 1050', 'e ) none of the above']
Output:
a