I spent some time in the Navy working on an aircraft carrier as regular crew. Often, after or during, a hard days work, I would have the opportunity to look down on the flight deck from high up on the island. From there I could see the Airedales preparing for aircraft launch and recovery operations. It was amusing to watch a long line of them walking abreast from one end of the ship to the other stooped low in sort of a duck walk. What they were doing was excruciatingly important. They were looking for any object that could cause foreign object damage to the engines or airframes of the aircraft. I would see one of them pause every now and then to pick up an object that was too small for me to make out. It might have been a screw or some other fasterner. It may have been tiny but it was significant enough to pick up.

Let's make it clear, no object of any size or hardness belongs in the flight path of any airplane. There are plenty of federal regulations that apply to these situations. I expect the FAA and local law enforcement to enforce them brutally.

By the way, my answer is: all of the above.