To answer this question, we need to understand what an ARCn process is and its relationship with an instance.
An ARCn process stands for Asynchronous Refresh Control process. It is used in Oracle databases for automatic refreshing of materialized views.
In Oracle databases, an instance refers to the memory and processes associated with a running Oracle database. Each instance can have multiple background processes, including ARCn processes.
The correct answer is D) ten. An instance can have up to ten ARCn processes associated with it. These processes are responsible for refreshing materialized views asynchronously.
Therefore, the correct answer is D) ten.