The option that describes a process explanation is a step-by-step process, such as a math formula or a scientific technique.
A process explanation is a type of explanation that focuses on a specific pattern of organization. It concentrates on the step-by-step organization, which means it pays great attention to the steps or stages of a certain process. In that way, the main aim of the process explanation is to help the reader to understand each of these stages. Generally, an introduction is included in this piece of writing in order to define the process that is going to be explained.