Answer:
A hollow cylinder
Explanation:
A rectangular prism utilizes sharper angles, and would be true if it stopped and turned 90 degrees at 4 corners.
A flat disk would be true if it didn't have any length
A square pyramid. I don't know how you would get a square pyramid
The cylinder is the best answer, because the rotation is curved with a length L (length of the rectangle) and it is not thick enough to fully cover the inside so it is hollow.
