Final answer:
Drawing from the context of the passage, Markus appears to be demonstrating social networking professionalism by maintaining a professional profile online. Future opportunities, such as college admission or job offerings, could be affected by one's social media presence, emphasizing the need for a professional and responsible approach to social networking.
Step-by-step explanation:
The passage provided suggests that Markus is demonstrating social networking professionalism by being careful about what he posts online. In none of the excerpts is it explicitly stated how Markus is behaving on social media; however, the context implies that he is likely maintaining a professional image and is aware of the potential long-term repercussions of his online activity.
Professionalism on social networking sites often involves maintaining a presentable profile, being mindful of the content shared, and considering the impact of online behavior on future opportunities. This type of professionalism is important because employers and colleges may review social media profiles to assess a candidate's suitability for admission or employment. The passage emphasizes the importance of avoiding the posting of negative thoughts or personal frustrations, as they can lead to negative consequences, such as the example given with comedian Kevin Hart.
Therefore, the most likely answer to what kind of professionalism Markus is using would be (a) He was maintaining a professional profile, since that encompasses the importance of a responsible social media presence as underscored in the provided text.