What is a Data Extension's Customer Key, and why would you reference it in an API call?

What is a Data Extension's Customer Key, and why would you reference it in an API call?

• A. The Customer Key uniquely identifies the Data Extension for API calls; referencing it ensures you access the correct DE regardless of its name.
• B. The Customer Key is the friendly name used in UI for labeling.
• C. The Customer Key is the primary key of records inside the DE.
• D. The Customer Key is used only for deletion operations via API.

Answer: (B)