Final answer:
In an IoT healthcare monitoring system, an alert that must be acknowledged by the patient exemplifies two-way communication, which involves both sending information and receiving a response.
Step-by-step explanation:
In an IoT healthcare monitoring system, when a system sends out an alert which the patient is required to acknowledge, this is an example of c) Two-way communication. This scenario involves the system initiating a message or alert to the patient (which would be one-way communication), and then the patient responding back to confirm receipt or take action, which completes the loop, thus making it two-way. Although push notifications can be a part of this process, they are typically considered one-way. Real-time feedback and sensor data transmission are also aspects of a monitoring system but are not directly related to the acknowledgment of a message by the patient, which characterizes two-way communication.