Final answer:
Users did not want service chatbots to ask for personally-identifiable information, even when the transaction was productive. The correct option is a.
Step-by-step explanation:
When it comes to service chatbots, users did not want the aspect of asking for personally-identifiable information, even when the transaction was considered productive. This is because users value their privacy and may not feel comfortable sharing personal information with a chatbot.
The other options provided in the question, such as displaying emotions in the wording of their responses, keeping a transcript of the text exchange after the call ends, and using abbreviations (text-speak) in messages, are not mentioned as aspects that users did not want. The correct option is a.