Final answer:
The number of people a user can import via CSV at one time varies with the system being used; many systems would allow up to 100 or an unlimited number of entries per import, but it's best to check the specific service's documentation or support resources.
Step-by-step explanation:
The number of people a user can import via CSV at one time can vary depending on the specific platform or service being used. However, many modern systems and business tools typically allow for a large number of entries to be imported at once. If we assume the question is about a commonly used system, such as a CRM or a user management tool in a web application, options can range from small batches of 10 or 50, to large batches of 100 or more, and even up to unlimited entries depending on the system's capacity and the limits set by the service provider.
Without specific constraints provided, the safest assumption would be option 4, which is unlimited. Yet, it's always best to consult the documentation or support resources of the specific service or system in question to confirm the exact number of records allowed per batch import.