The force which a magnet exerts on iron and steel is called the
magnetic force
Step 1. The explanation for the correct option:
Option B.
Step 2. The explanation for incorrect options:
Option A.
An electric force is an attracting or repulsive interaction between any two charged things.
Option C.
The nuclear force is the interaction of protons and neutrons in atoms.
Option D.
Gravity, often known as gravitation, is the universal force of attraction that acts between all matter in mechanics.
Therefore, The force which a magnet exerts on iron and steel is called the magnetic force.
Hence, option B is correct.