正解:C
Job scheduling is a core operational control that ensures workloads are executed in an orderly and efficient manner, balancing demands across processing resources. Its primary benefit is optimization of system resources-CPU, memory, I/O, and network bandwidth-leading to improved throughput and consistent service levels. While scheduling may indirectly reduce downtime (A) or support scalability (B), its direct impact is ensuring resources are allocated efficiently. Decreasing complexity (D) is not the key purpose of scheduling. ISACA's DSS01 (Managed Operations) recognizes workload and job scheduling as crucial practices for sustaining reliable, high-performance IT services.
References (ISACA): COBIT 2019, DSS01 Managed Operations.