A customer's regulatory requirements are to have valid disk-based data at the recovery site regardless of any equipment or logical failure in the system or environment and have the ability to test…

A customer's regulatory requirements are to have valid disk-based data at the recovery site regardless of any equipment or logical failure in the system or environment and have the ability to test recovery non-disruptively. What is the minimum number of disaster recovery site point-in-time copies required to perform recovery testing?