What type of good is characterized by the fact that one person's use does not diminish its availability to others, and it is difficult to prevent anyone from accessing it?

Explanation

A private good is rivalrous and excludable, meaning consumption by one reduces availability for others. A merit good is socially desirable but not necessarily non-excludable. A public good is non-rivalrous and non-excludable, fitting the description given. An abundant good refers to plentiful resources but not necessarily non-excludable. Therefore, the correct answer is public good.