Answer: Option (A) is the correct answer.
Explanation:
Magnetic shielding is not provided by aluminium as its permeability is on. On the other hand, plastic is not able to protect magnetic fields passing through it. Therefore, plastic cannot be used to protect magnetic shielding.
Whereas stainless steel is not a magnetic material and therefore, it does not allow magnetic field to pass through it.
Thus, we can conclude that a box constructed of sheets of steel materials can be used to shield magnetic fields from the inside of a box.
