This is a test of commonsense with single/multi-choices. Complete the next sentence:

How to use wall plugs and screws
Determine if you need to use wall plugs, or if you can hang an item on a stud.
Purchase or rent a stud finder and mark the locations on your walls. If those areas don't match up with the project, then move on to finding wall plugs and screws that will work.

Choices: 1. Consult with your drywall company, architects, or contractors to see what they recommend for your project, or ask your construction peers. Create a space for wall plugs.; 2. Locate the flooring location you want to hang the object. If you plan to hang something on a wall, it's necessary to find the floor or otherwise work with it.; 3. Installation in the center of a stud is always preferred, because it is a load-bearing support. Walls, especially dry wall, are not designed to hold large, heavy objects by themselves.; 4. Determine where to put stud finder and screw finder. Use a straight edge from the wall finder to mark where you will put the stud finder and screw finder.;
The answer is:
3.