________ is an application layer protocol for resource constrained devices.2 pointsCoAPHMTPMQTTTCP/IP

The application layer protocol specifically designed for resource-constrained devices is MQTT (Message Queue Telemetry Transport).

Details:

1. MQTT is a lightweight messaging protocol that is optimized for high-latency or unreliable networks.
2. It is designed to be simple and efficient, making it ideal for use in situations with limited processing power and bandwidth, commonly found in IoT (Internet of Things) environments.
3. The protocol operates on the publish-subscribe model, which allows for efficient communication between devices.

In summary, MQTT stands out among the listed options due to its appropriateness for resource-constrained applications, particularly in IoT scenarios.