Final answer:
XYZ Corporation is providing a public good by creating a park, which offers non-excludable and non-rival benefits to the community, illustrating a positive externality.
Step-by-step explanation:
When XYZ Corporation decided to build a park in front of its corporate office, it was providing a public good to the neighboring community. A public good is characterized by its non-excludability and non-rivalry, meaning that no one can be prevented from using it and one person's use does not reduce its availability to others. While the government provides important public services like national defense and education, it is not the sole provider of public goods. In this case, the corporation contributes a positive externality, which is a benefit that is enjoyed by those who did not directly pay for it. The park offers benefits such as aesthetic enjoyment and recreational space, which are accessible to the entire community without direct compensation to XYZ Corporation.