Permeance is the reciprocal of

The correct answer is B. Reluctance.

Permeance is the ability of a material to allow magnetic flux to pass through it. It is the reciprocal of reluctance, which is the resistance of a material to the passage of magnetic flux.

The other options are not correct because they are not related to magnetic flux.

• Flux density is the amount of magnetic flux per unit area.
• Ampere turns is the product of the number of amperes and the number of turns in a coil.
• Resistance is the opposition to the flow of electric current.