The correct answer is A. current.
A fuse is a safety device that is used to protect electrical circuits from damage caused by excessive current. The fuse rating is the maximum current that the fuse can safely carry. If the current in the circuit exceeds the fuse rating, the fuse will blow, which will open the circuit and prevent damage to the equipment.
Option B, voltage, is the electrical potential difference between two points. It is measured in volts (V). The voltage rating of a fuse is the maximum voltage that the fuse can safely withstand. If the voltage in the circuit exceeds the fuse rating, the fuse may fail, which could cause damage to the equipment.
Option C, VAR, is a unit of reactive power. Reactive power is the component of electrical power that does not produce work. It is measured in volt-ampere reactive (VAR). The VAR rating of a fuse is not typically specified, as it is not a factor in the fuse’s ability to protect the circuit.
Option D, kVA, is a unit of apparent power. Apparent power is the product of the voltage and current in a circuit. It is measured in kilovolt-amperes (kVA). The kVA rating of a fuse is not typically specified, as it is not a factor in the fuse’s ability to protect the circuit.