Circuit breakers are made to cut off power to an electrical circuit when too much amperage is strained through the wires. Different size wires are used to carry more or less amperage. For example, a 14 gauge wires are usually set with 15 amp breakers while 12 gauge wires are usually set with 20 amp breakers. Breakers protect you in the event you are drawing too much power through a single circuit. So, the answer is C – 15A or 20A.