What should a Data architect implement to make changes efficiently?

Universal Containers (UC) is going thought major reorganization of their sales team. This would require changes to a large a number of group members and sharing rules. UCs administrator is concerned about long processing time and failure during the process.

What should a Data architect implement to make changes efficiently?
A . Log a case with salesforce to make sharing rule changes.
B . Enable Defer Sharing Calculation prior to making sharing rule changes.
C . Delete old sharing rules and build new sharing rules
D . Log out all users and make changes to sharing rules.

Answer: B