Answer:
A. electricity
Step-by-step explanation:
Electricity is a private good because it is excludable and rivalrous. Excludable means that people can be prevented from consuming it, and rivalrous means that one person's consumption of it reduces the availability of it for others. For example, if I pay for electricity, I can prevent you from using it by turning off the breaker to my house. And if I use a lot of electricity, there will be less electricity available for you to use.