Final answer:
Small computer terminals inside ambulances that directly receive data from the dispatch center are modems.
Step-by-step explanation:
The small computer terminals inside ambulances that directly receive data from the dispatch center are modems. Modems are devices that allow computers to communicate over a network, in this case, the dispatch center.
Although radios and GPS devices can also transmit and receive data, they are not specifically designed for direct communication with a dispatch center. Mobile phones can also receive data, but they are not typically used as the primary communication device in ambulance dispatch systems.