Task: Question Answering
Input (English): Problem: a box measuring 36 inches long by 45 inches wide by 18 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 ) 32 , b ) 34 , c ) 38 , d ) 40 , e ) 42
Output (English): d