What would be the best approach to achieve this in SAP Sales Cloud Version 2?

As a Sales Manager, you want to require the Sales Representatives to update the Revenue End Date when Opportunities are in the "Close" sales phase.

What would be the best approach to achieve this in SAP Sales Cloud Version 2?
A . Configure a Playbook with a mandatory Action to update field.
B . Configure a Playbook with a mandatory Activity to update field.
C . Configure a Playbook with an Action to update field.
D . Configure a Playbook with an Activity to update field.

Answer: A