Task: Question Answering
Input (English): Problem: a lady builds 7 cm length , 18 cm width , and 3 cm height box using 9 cubic cm cubes . what is the minimum number of cubes required to build the box ? 
Options: ['a ) 42', 'b ) 45', 'c ) 47', 'd ) 49', 'e ) 56']
Output (English): a