Which storage solution will be an ideal storage solution at the edge when the data (images and videos) is required to be stored locally at the edge until the data (images and video) is processed?

Answer options:

A.Azure Blob Storage on IoT Edge
B.Azure IoT edge stream device
C.Apache Spark
D.Azure IoT Edge parallel storage

Correct Answer: A
Option A is CORRECT.
Azure Blob Storage on IoT Edge is useful for many scenarios including below: 
-When local data storage is needed until either processing of data is done or the data is transferred to the cloud. 
-If the devices are located at locations with limited connectivity. 
-In scenarios when latency is to be minimized and hence the data is to be processed locally. 
-In the scenarios when bandwidth costs are to be reduced and transferring huge data to the cloud is to be avoided. Option B is INCORRECT. Azure IoT edge stream device is an invalid choice.
Option C is INCORRECT.Apache Spark is a Parallel processing framework supporting in-memory processing for boosting big-data analytic applications performance. Microsoft`s implementation of Apache Spark in Azure is “Apache Spark in Azure HDInsight.”
Option D is INCORRECT.Azure IoT Edge parallel storage is an invalid option.
References: 

https://docs.microsoft.com/en-us/azure/iot-edge/how-to-store-data-blob
https://docs.microsoft.com/en-us/azure/hdinsight/spark/apache-spark-overview