You have to build an IoT solution which gathers traffic data from 400 devices, with the expected workload of 4000 messages per minute. For processing this dataflow, you decide to provision one S2 IoT Hub unit. In most of the time, the distribution of the messages is uniform, but around peak hours, short spikes (as much as 120 messages per second) might occur in the flow of data. Being aware of this pattern, you are sure that it will cause no problem in the message ingestion. 
Is that a valid assumption?

Answer options:

A.No, because IoT Hub’s throttling takes effect immediately when number of messages per second exceeds cca. 70 messages/s and the excess messages will be rejected
B.Yes, because even if throttling takes effect, temporary burst in the message flow are tolerated by the IoT Hub and no problem occurs
C.Yes, because S2 hubs can process as much as 200 messages/second with no problem
D.No, because S2 hubs are designed to accommodate a uniform flow of messages with no spikes

Correct Answer: B
Option A is incorrect because the throttling takes effect at 120 messages/s. In addition to that, the IoT Hub accepts requests even above the throttle threshold for a limited time.
Option B is CORRECT because in spite of the automatic throttling, the IoT Hub accepts requests above the throttle threshold for a limited time. If the spikes are a few seconds long, the traffic shaping feature will cope with these bursts.
Option C is incorrect because the total number of edition 2 hubs is 4167 messages/min/unit, i.e. 69 messages/s/unit. 200 is well beyond the capability of this type of hub.
Option D is incorrect because of course, IoT hubs of any tier can accommodate a randomly variable flow of messages within its quota and throughput limitations.
References: 

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