So, we are looking for how many quires can fit into a ream. All we have to do is divide the number of sheets in a ream (100) by the number of sheets in a quire (25) because dividing allows us to see how many times a specific number can go into another number, which is what we are looking for. (How many quires are in a ream).
The cross-section of a square pyramid will be a square. The section above the cross-section taken will basically be a similar but smaller square pyramid. D is the correct answer.
