Capacitors are used in electrical circuits where appliances need rapid:-
(A) Current
(B) Voltage
(C) Watt
(D) Resistance

Hint : In this, we find out why capacitors are used in electrical appliances and why these appliances need a capacitor. A capacitor is a device that stores electrical energy in the form of an electrical field. But a capacitor does not have a new electron that means it does not produce electrical energy on its own.

Complete step-by-step answer: The capacitor is a little like a battery. Although they work in completely different ways, both capacitor and battery store electrical energy. A capacitor is much simpler than a battery, as it cannot produce new electrons; it only stores them. When the capacitor is charged the capacitor has the same voltage as the battery if a battery has 1.5 volts that means the capacitor has the same voltage of 1.5 volts.
A capacitor can store electric energy when it is connected to its charging circuit. And when it is disconnected from its charging circuit, it can dissipate that stored energy, so it can be used like a temporary battery. Capacitors are commonly used in electronic devices to maintain their power supply and some appliances need rapid current so they can start.
Even nature shows the capacitor at work in the form of lightning. One plate is the cloud, the other plate is the ground and the lightning is the charge releasing between these two plates. The capacitor provides a high amount of current, which is required for the electrical appliances some of the circuits require more current than the other circuits
So the capacitors are used in electrical circuits where appliances need current.

Option A is the correct answer.

Note: To understand this question we have to learn about capacitors, how they charge how they work, what amount of charge they store and what type of charge they store in what type of circuits they have used types of capacitors so we can easily understand the concept of this question. After learning these terms we can easily answer these types of questions.