Which system is used in hotels to monitor and manage outgoing phone calls?

The correct choice is Call Accounting, which is specifically designed to monitor and manage outgoing phone calls within hotel operations. This system tracks various aspects of telecommunication services, such as the duration of calls, time of calls, destination numbers, and associated costs. By using a Call Accounting system, hotels can efficiently manage their communication resources, ensure billing accuracy, and analyze call patterns, which can be helpful in identifying trends for both operational and financial decision-making.

In contrast, Reservation Management systems focus on handling guest bookings and availability, Guest Tracking systems monitor guest activities and preferences during their stay, and Room Management systems deal with the status of rooms and housekeeping schedules. None of these options serve the specific purpose of monitoring outgoing phone calls effectively.