According to the Microsoft Learn module “Build a QnA Maker knowledge base”, QnA Maker allows developers to create bots that answer user queries based on documents like FAQs or manuals. To make a bot more natural and conversational, Microsoft provides a “chit-chat” feature — a prebuilt, professionally written set of responses to common conversational phrases such as greetings (“Hello”), small talk (“How are you?”), and polite phrases (“Thank you”).

Adding chit-chat improves user experience by making the bot sound friendlier and more human-like. It doesn’t alter the main Q & A logic but enhances the bot’s tone and responsiveness.

The other options are not correct:

A. Increase the confidence threshold makes the bot more selective in responses but doesn’t add new conversational features.

B. Enable active learning improves knowledge base accuracy over time through user feedback.

C. Create multi-turn questions adds conversational flow for related topics but doesn’t add greetings or casual dialogue.

Thus, to make the bot more personable, the correct action is to Add chit-chat.