In outsourced IT services, the RTO is defined within the SLA.

B (Support availability):Defines hours of service and whether support is available 24/7 or during business hours.

E (Resolution time):Specifies the timeframe within which the service provider commits to resolve incidents.

Other options explained:

A: Cost and size are contractual, not SLA performance metrics.

C: Sustainability is long-term environmental or operational, not SLA-specific.

D: Reliability is often captured as uptime or availability but not as a discrete SLA support term.