How can the system administrator accomplish this?

Sales reps at AW Computing need assistance from product managers when selling certain products. Product managers do not have access to Opportunities but need to gain access when assisting on a specific deal.

How can the system administrator accomplish this?
A . Notify the product manager using opportunity update reminders
B . Use similar opportunities to show opportunities related to the product manager
C . Enable account teams and allow users to add the product manager
D . Enable sales teams and allow users to add the product manager

Answer: D