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. Should you have additional questions, you can always mark the followup back to Unresolved again. 

You can use the helpful link below a followup post to mark it as a good contribution:

To reply to a followup, simply type your response into the text box beneath the followup itself: