A disaster recovery plan for an organization's financial system specifies that the recovery point objective (RPO) is no data loss and the recovery time objective (RTO) is 72 hours. Which of the following is the MOST cost-effective solution? 
A、A hot site that can be operational in eight hours with asynchronous backup of the transaction logs 
B、Distributed database systems in multiple locations updated asynchronously 
C、Synchronous updates of the data and standby active systems in a hot site 
D、Synchronous remote copy of the data in a warm site that can be operational in 48 hours