You create an Azure Cosmos DB for NoSQL container. You must use the .NET SDK to implement a client application that will process each individual change to items in the container. You need to create a change feed processor by using the .NET SDK.

What should you do first?
a. Invoke the StartAsync method.
b. Invoke the GetChangeFeedProcessorBuilder method.
c. Create a partition to scope the database transactions.
d. Create a container class instance for both the source and lease containers.