A CIO is concerned that critical applications take too long to recover. Which cloud capability improves business continuity?

High availability ensures that applications and services remain operational even if a component fails, minimizing downtime and improving recovery times. This directly addresses the CIO's concern about applications taking too long to recover, as it focuses on continuous operation and rapid restoration of service. Cost optimization is about reducing expenses, not directly improving recovery. Metered billing is a pricing model and doesn't inherently impact business continuity. Vertical scaling increases the resources of a single instance, which can improve performance but doesn't inherently provide the redundancy and fault tolerance needed for improved recovery in the face of failures.