The correct answer is C. To persuade
Step-by-step explanation:
In texts, to persuade is one of the most common purposes, this focuses on convincing the audience about one idea or action by providing reasons or evidence. The piece of media writing is an example of this because the writer tries to convince the reader to "buy produce only at farmers' markets" and for doing this the author provides reasons and evidence such as "fresh and nutritious food to the average consumer", "strict quality standards" and "you’ll support small farmers" that are positive aspects related to buying at farmers' markets.