<human>: Objective: What is an easy way to find the exact location of a stud behind dry wall?

Which of the following solutions is more sound in terms of naive physics reasoning?

OPTIONS:
- Push a long nail through the areas of the wall where you think the stud is located until you hit metal.
- Run a magnet along the area of the wall you think the stud may be located until you feel resistance.
<bot>: Run a magnet along the area of the wall you think the stud may be located until you feel resistance.