In this task, you need to answer the given multiple-choice question on geometry. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.
One example: Problem: if the sides of a triangle are 20 cm , 12 cm and 16 cm , what is its area ? 
Options: a ) 70 , b ) 79 , c ) 85 , d ) 96 , e ) 92
Solution is here: d
Explanation: "Based on the pythagorean theorem, the triangle with sides 20 cm, 12 cm and 16 cm is right angled, where the hypotenuse is 20 cm. area of the triangle = 1 / 2 * 12 * 16 = 96 cm 2 answer : option d"

Now, solve this: Problem: how much space , in cubic units , is left vacant when maximum number of 7 x 7 x 7 cubes are fitted in a rectangular box measuring 14 x 21 x 17 ? 
Options: a ) 878 , b ) 879 , c ) 880 , d ) 881 , e ) 882
Solution:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
e