Universal Containers has a public sharing model for accounts and uses the parent account field to create a multi-level account hierarchy. When viewing a parent account, the company would like to see the total value of open opportunities for all accounts in the hierarchy. What solution should a consultant recommend to meet this requirement?
                
                                        
                        A. Use apex to update a custom field on the parent account with the total value of open opportunities from the child accounts                    
                                        
                        B. Create a roll-up summary field on the parent account showing the total value of open opportunities from the child accounts                    
                                        
                        C. Define a workflow rule to update the custom field on the parent account with the total value of open opportunities from the child accounts                    
                                        
                        D. Create a link on the account that opens a report showing the total value of open opportunities for all the accounts in the hierarchy