Which of the following windowing features would you use to output the events only when the content of the window really changed in Stream Analytics jobs? 

Answer options:

A.Tumbling Window
B.Topping Window
C.Sliding Window
D.Session Window
E.Snapshot Window

Correct Answer: C 
It is the sliding window that outputs the events only when the content of the window really changed in Stream Analytics jobs.Option A is incorrect. A Tumbling window function segments a data stream into a contiguous series of fixed size, non-overlapping time segments and works against them.
Option B is incorrect. There is no windowing function like Topping Window.
Option C is correct. The sliding window function is used to output the events only when the content of the window really changed in Stream Analytics jobs. 
Option D is incorrect. Session window function groups events arriving at similar times, filtering out points/periods of time where there exists no data.
Option E is incorrect. The snapshot window function is used to group the events having the same timestamp.
Reference: 
To know more about Windowing functions, please visit the below-given link: 

https://docs.microsoft.com/en-us/learn/modules/ingest-data-streams-with-azure-stream-analytics/6-describe-windowing-functions