Final answer:
The main purpose of the article is likely to inform the reader about the possible benefits of gum chewing, emphasizing the educational aspect and presentation of information.
Step-by-step explanation:
To determine the main purpose of an article, we should look at the key points being discussed and how the information is presented. In this case, if the article's focus is on the benefits of chewing gum, for instance, how it could improve memory or concentration, and presents scientific evidence or expert opinions to back up the claims, it's likely that the main purpose is to inform the reader about those potential benefits. This would suggest that option 4, 'To inform the reader about some possible benefits of gum chewing,' is the correct answer.
If the article includes persuasive elements, such as making the reader feel like they should try chewing gum during a test or encouraging a specific behavior related to gum chewing, it could be argued that it also has a persuasive element, potentially making option 2 a secondary purpose. However, without the precise content of the article, we should focus on the most evident purpose based on the information provided.