You haven't told us whether the rectangular prism is the size of a pack of gum or more like the size of a cruise ship.
Whatever size it is, here's the number of centimeter squares you need to cover the whole outside of it:
(2 x length x width) + (2 x length x height) + (2 x width x height)
with all measurements made in centimeters.
Answer:
Prime.
Step-by-step explanation:

First let's multiply our outer coefficients in this case 1 and 8, so we have 1x8=8. Now the point of this is to get the factors of 8 and see if we can get that middle term -7. Factors of 8 are 1x8, 2x4 and that's it. From there I notice that -8+1 = -7 and so:

Notice that the (x-8) and (x+8) are not the same factors, therefore the factors are not any of those answer choices and so it's prime. You can calculate the factors by using the quadratic formula, however I think that is beyond the scope of this question.