The magnitude of the magnetic field of a current carrying conductor increases with increase in ____________.

Correct option is D

The correct answer is (D) Current.

The magnitude of the magnetic field of a current-carrying conductor increases with the increase in the current flowing through it. 

This is because the strength of the magnetic field is directly proportional to the magnitude of the current. 

Explanation:

• A conductor is an object or material that allows the flow of charge. 
• When a current flows through a conductor, the charges are always moving, which produces a magnetic field around the conductor. 
• The magnitude of the magnetic field produced by a current-carrying conductor decreases as the distance from the conductor increases.