To comment or post a followup question to a Q&A post, please click within the text box beneath the post that reads "Compose a new followup discussion."
When a new followup is posted, it will automatically be set to "Unresolved," and an icon reading "1 unresolved followup" will display beneath the post in your Q&A feed, as seen below.
You and your classmates can resolve a followup by selecting "Resolved" just above the followup, as seen below. However, should you have additional questions, you can always mark the followup back to "Unresolved" again.
To reply to a followup, simply type your response into the text box beneath the followup itself.