You are working for a company which is about setting up a country-wide environmental monitoring system for real-time air pollution monitoring. The system, in the first stage, will consist of 10000 sensor end-devices deployed all over three regions. Your task is to connect these devices to an Azure IoT solution. Because of the large number of devices, you decide to use three IoT Hubs, with the Device Provisioning Service. 
Which is the best allocation policy you should use to distribute the device connections over the hubs?

Answer options:

A.Hashed distribution
B.Distribution by lowest latency
C.Evenly weighted distribution
D.Static configuration via enrollment list

Correct Answer: B
Option A is incorrect because there is no allocation policy named “Hashed distribution”. Hashed distribution is applied by DPS in the case of Lowest latency, when more than one linked IoT hubs can provide the same latency.
Option B is CORRECT because in order to get the best performance and an actual real-time behavior, the best solution is to allocate the devices to the IoT Hub with the lowest latency. The built-in “Lowest latency” allocation policy is the best choice here.
Option C is incorrect because with the Evenly weighted distribution (which is the default allocation policy) the requirement of real-time behavior will not be touched. In the case of several IoT hubs, the solution should be optimized for latency.
Option D is incorrect because distribution by static configuration will not take into account the latency (real-time) requirement. In addition, it doesn’t make use of the DPS’s built-in automatism.
Reference: 

https://docs.microsoft.com/en-us/azure/iot-dps/