How can a Salesforce architect help IK to Improve sales reps productivity?

Sales reps at Universal Containers (UC) complain about the manual activities they need to perform in order to grant access to supporting internal users (legal, engineering, finance, and so forth) for customer records when they need help. In general, the sales reps involved in the deals will not change.

How can a Salesforce architect help IK to Improve sales reps productivity?
A . Create a permission set with "view all data" and assign to supporting users.
B. Create a public group and replace the account ownership with it.
C. Create a criteria-based sharing rule to grant access to other users.
D. Leverage default Account team.

Answer: C,D