What strategy should the data architect implement to satisfy this requirement?

Marketing: All email, SMS, and social campaigns for a customer

Customer service agents using Salesforee would like to view the activities from all four systems to provide support to customers. The information has to be current and real time.

What strategy should the data architect implement to satisfy this requirement?
A . Explore external data sources in Salesforce to build a 360 degree view of the customer.
B. Use a customer data mart to create the 360 degree view of the customer.
C. Periodically upload summary information in Salesforce to build a 360 degree view.
D. Migrate customer activities fro, all four system into Salesforce.

Answer: A