How should the documents be shared efficiently and securely?

Northern Trail Outfitters (NTO) wants the ability to share documents related to an opportunity, such as contracts and proposals, with the field sales team. NTO currently has a private sharing model.

How should the documents be shared efficiently and securely?
A . Emailed to the sales team on the opportunity record
B . Uploaded to a library that is shared with the field sales organization
C . Uploaded to Salesforce Files and shared with the field sales organization
D . Uploaded to Salesforce Files from the opportunity record

Answer: C