Answer:
A chat system
Explanation:
In order for Janis to be able to respond to customer inquiries in real time, she should use an instant messaging system, or chat system.
Normally, this would be integrated into the company's Web site.
That would allow the customers to contact Janis directly and in real time, without the need to send emails and await for a respond, which might come later or being forgotten (by either side).
