Reluctance is the measure of opposition offered by a magnetic circuit to the flow of magnetic flux. It is analogous to resistance in an electrical circuit. In an electrical circuit, resistance opposes the flow of electric current, while in a magnetic circuit, reluctance opposes the flow of magnetic flux.

Explanation:

1. Electrical Circuit:
- In an electrical circuit, the flow of electric current is determined by the voltage applied and the resistance encountered.
- Resistance is the property of a material or component that opposes the flow of electric current. It is measured in ohms (Ω).
- The higher the resistance, the greater the opposition to the flow of current.

2. Magnetic Circuit:
- In a magnetic circuit, the flow of magnetic flux is determined by the magnetomotive force (MMF) applied and the reluctance encountered.
- Reluctance is the property of a magnetic circuit that opposes the flow of magnetic flux. It is measured in ampere-turns per weber (A-turns/Wb).
- The higher the reluctance, the greater the opposition to the flow of magnetic flux.

Relation between Resistance and Reluctance:
- Resistance and reluctance are analogous to each other in their respective domains.
- Just as resistance determines the flow of electric current in an electrical circuit, reluctance determines the flow of magnetic flux in a magnetic circuit.
- Both resistance and reluctance depend on the physical properties of the material or component through which the flow occurs.
- In an electrical circuit, resistance depends on factors such as length, cross-sectional area, and resistivity of the material.
- Similarly, in a magnetic circuit, reluctance depends on factors such as length, cross-sectional area, and permeability of the material.

Conclusion:
- The electrical equivalent of reluctance is resistance.
- Both reluctance and resistance represent the opposition encountered in their respective domains - magnetic circuit and electrical circuit.
- While reluctance opposes the flow of magnetic flux, resistance opposes the flow of electric current.
- Therefore, option 'A' - Resistance is the correct answer for the electrical equivalent of reluctance.