Which of the following are examples of public goods?

Public goods are characterized by being non-excludable and non-rivalrous, meaning they can be used by anyone without preventing others from using them, and one person's use does not diminish another's. In the given options, a lighthouse, national defense, and a public park are examples of public goods. A lighthouse provides a signal to all ships without excluding others or reducing its availability, national defense protects all citizens without limiting the protection of others, and a public park is generally open for everyone to enjoy. In contrast, a laptop and a restaurant meal are not public goods because they are excludable (only those who pay can use them) and rivalrous (their use by one person prevents use by another).