A ticket classifier uses a closed enum of five categories. New kinds of tickets, such as accessibility complaints, are being forced into "billing" or "technical," and the team can't see how often this happens. What is the best schema change?

Answer: A — Add an "other" enum value with a detail string naming the actual category

An "other" value plus a detail string keeps the classification honest for extensible categories and shows which new categories to add. Free text (b) gives up the structure downstream systems rely on. "Pick the closest" (c) is the current misclassification. Rejecting tickets (d) drops legitimate work.