help with this DFD question

At the Meet \& Greet Hotel, the Booking Information System receives a booking request from the Guest, and then the Booking Information System checks the availability of rooms for the requested dates by sending an enquiry on room availability to Room Scheduling System, which will answer the enquiry by sending back a list of available rooms. The Booking Information System then will create the reservation after receiving the Payment Method from the Guest and validate the payment by sending payment validation request to the Bank. Once the Bank validates the payment method it will send back payment confirmation. Finally, the Booking Information System will seno booking confirmation to the Guest