Business continuity is the discipline specifically focused on ensuring that an organization's critical business functions and applications continue to operate, with uninterrupted and reliable access to the data and systems they depend on, across a wide range of potential disruptions, encompassing proactive resiliency architecture (redundancy, high availability, replication) designed to prevent or minimize any interruption in the first place, rather than only reacting after an outage. This directly matches the scenario's specific emphasis on continuous, reliable, uninterrupted access, which is the defining objective of business continuity as a discipline. Data encryption (B) protects the confidentiality of data against unauthorized disclosure, an important but entirely separate concern from ensuring continuous availability and access; encrypted data that becomes unavailable due to an outage is still unavailable, regardless of how well it is encrypted. Disaster recovery (C) is closely related but narrower in scope and reactive in nature, specifically concerned with restoring systems and data after a significant disruptive event has already occurred, whereas the scenario emphasizes ongoing, uninterrupted access, a broader and more proactive goal that business continuity, as the umbrella discipline (of which disaster recovery is one component), more precisely addresses. Data backup (D) provides recoverable copies of data in case of loss but does not, on its own, ensure continuous or uninterrupted access to that data during normal operations. Business continuity is correct.

Reference topic: Data Protection and Management Introduction - Business Continuity as a Core Objective.