What is the recommended way to accomplish this task?

Universal Containers needs their channel partners to collaborate on Opportunities within their new partner Community based on the Customer Service Template .

What is the recommended way to accomplish this task?
A . Create a page layout for leads and assign it to those profiles that have access to the Community.
B . Create a Detail page for invoices and add the page as a Navigation Menu item.
C . Create a Visualforce page for Opportunities and add the page as a Navigation Menu item.
D . Add Opportunities as a Salesforce Object in the Navigation Menu.

Answer: D