Answer: C. a positive externality.
Explanation:
The positive externality refers to actions that directly or indirectly present benefits to society. Sometimes these activities are paid for third parties, likewise, it can be seen that each action that is carried out, however small, will have effects on people (society) causing a positive externality.
For example, in the case of the neighbor, there is a positive externality, since his ability with the garden gives the neighborhood a nice touch, although some plants are not liked by some neighbors, you can see different and beautiful things in the neighbor's garden, and this benefit is being obtained at no cost to others since the person who invests is a person and the others also enjoy the benefits of it.
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