Which two approaches will accomplish this goal?

Get Cloudy Consulting is migrating their legacy system’s users and data to Salesforce. They will be creating 15,000 users, 1.5 million Account records, and 15 million Invoice records. The visibility of these records is controlled by a 50 owner and criteria-based sharing rules.

Get Cloudy Consulting needs to minimize data loading time during this migration to a new organization.

Which two approaches will accomplish this goal? (Choose two.)
A . Create the users, upload all data, and then deploy the sharing rules.
B. Contact Salesforce to activate indexing before uploading the data.
C. First, load all account records, and then load all user records.
D. Defer sharing calculations until the data has finished uploading.

Answer: A,D