单选题A storage specialist is discussing the customer’s high availability plan and discovers that they areonly 80 kilometers （50 miles） from the intended site. They require 7 x 24 x 365 data availability in aUNIX environment with an RPO of two minutes. They 

A storage specialist is discussing the customer’s high availability plan and discovers that they areonly 80 kilometers （50 miles） from the intended site. They require 7 x 24 x 365 data availability in aUNIX environment with an RPO of two minutes. They have two DS5300 systems located at bothsites. Which of the following IBM storage functions best meets the customer’s businesscontinuance requirements？（）