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

Example Input: Problem: what is the max number of rectangular boxes , each measuring 5 inches by 2 inches by 7 inches , that can be packed into a rectangular packing box measuring 15 inches by 20 inches by 35 inches , if all boxes are aligned in the same direction ?
Options: a ) 200 , b ) 350 , c ) 100 , d ) 150 , e ) 120
Example Output: d

Example Input: Problem: what is the maximum number r of 27 cubic centimetre cubes that can fit in a rectangular box measuring 8 centimetre x 9 centimetre x 12 centimetre ?
Options: ['a ) 36', 'b ) 32', 'c ) 24', 'd ) 21', 'e ) 15']
Example Output: c

Example Input: Problem: the perimeter of an equilateral triangle is 60 . if one of the sides of the equilateral triangle is the side of an isosceles triangle of perimeter 45 , then how long is the base of isosceles triangle ?
Options: a ) 5 units , b ) 10 units , c ) 15 units , d ) 20 units , e ) 25 units
Example Output:
a