There is an Azure Stream Analytics pipeline in your environment.You are using a watermark delay metric for monitoring. You see a sudden rise in the value of the watermark delay metric. Which of the following can be a possible reason?

Answer options:

A.more input events and fewer resources
B.Not enough throughput within the input event brokers
C.Not enough Capacity for provisioned output sinks
D.None of the above

Correct Answers: A, B and C 
Watermark delay metric actually works by checking the job health and is agnostic to input and output patterns of job. 
There are several reasons which can cause the increase in this metric. When there is an increase in the volume of input events, the associated resources will not be enough to handle it eventually. Resources need to be scaled up according to the reading of this metric. 
There will be throttling when there is not enough throughput within the input event brokers or when there is not enough Capacity for provisioned output sinks. Options A, B and C are correct:They are some of the reasons for the increase in the watermark delay metric.
Reference: 
To know more, please refer to the docs below: 

https://azure.microsoft.com/en-us/blog/new-metric-in-azure-stream-analytics-tracks-latency-of-your-streaming-pipeline/
https://docs.microsoft.com/en-us/azure/stream-analytics/stream-analytics-time-handling#side-effects-of-event-ordering-time-tolerances