You have to build an IoT solution which gathers data from 400 devices, with the expected total load of 100000 messages per day. Most of the devices are smart sensors, ready to connect to the IoT Hub via MQTT, but some of them need to be connected via edge devices. You want to use advanced configurations to control the devices remotely and to distribute some logic to the edge devices. 
Which of the available IoT Hub tiers should you choose and why?

Answer options:

A.Basic tier; because it can comfortably serve the expected workload
B.Standard tier; because it supports MQTT protocol
C.Standard tier; because it supports edge devices
D.Either basic or standard tier are suitable

Correct Answer: C
Option A is incorrect because regardless of the number of messages, which actually can be served by any tier, support for edge devices is needed, which is only provided by the standard tier.
Option B is incorrect because while both basic and standard tiers provide MQTT support, the key requirement here is the communication with edge devices: it is only supported by standard tier.
Option C is CORRECT because the requirement clearly states that edge devices must be connected to the IoT Hub, both for cloud-to-device communication and for the need of local computational power. It is only the standard tier which fulfils these requirements.
Option D is incorrect because edge device support and cloud-to-device communication are only available in standard tier.
Reference: 

https://docs.microsoft.com/en-us/azure/iot-hub/iot-hub-scaling#basic-and-standard-tiers