Which recommendation meets this requirement?

A consultant is implementing a new Sales Cloud instance for Cloud Kicks (CK) that has a public sharing model for Accounts. Different sales reps own localAccounts that create a multi-level Account Hierarchy. CK needs to see the total number of closed won opportunities and the revenue value for all Accounts in the hierarchy when viewing 2 Parent Account.

Which recommendation meets this requirement?
A . Configure an after-save flow to update a custom field on the parent Account with the total value of opportunities from the child Accounts.
B . Create a Roll-Up Summary field on the parent Account with the total value of won Opportunities from the child Accounts
C . Create a workflow rule to update the custom field on the parent Account with the total value of won Opportunities from the child Accounts
D . Use the View Account Hierarchy option and include a custom Roll-Up Summary field with the total value of won Opportunities in the displayed columns.

Answer: A