Final answer:
The Recovery Point Objective (RPO) is a business continuity metric that specifies the maximum targeted period in which data might be lost from an IT service due to a major incident. It is different for each system within a business and is not necessarily equal to or less than the Recovery Time Objective (RTO).
Step-by-step explanation:
An RPO, or Recovery Point Objective, is a term used in the field of Business Continuity Planning and Disaster Recovery. It refers to the maximum acceptable amount of data loss measured in time. Therefore, option b is correct: RPO is different depending on each system at a business, as it is determined by the significance of the system and the data it holds to the operations of the business. An RPO is not necessarily the same for all systems since each might have different requirements for data backup frequency. Option c and d are incorrect because the RPO is not always equal to the RTO (Recovery Time Objective), which is the target time set for the recovery of IT and business activities after a disaster has struck, and there's no inherent rule that RPO should be less than the RTO. Each should be determined based on the individual needs and priorities of the business.