ITIL V3's core structure is organized around the Service Lifecycle (ciclo de vida del servicio), which consists of five stages: Service Strategy, Service Design, Service Transition, Service Operation, and Continual Service Improvement. This lifecycle approach is the fundamental organizing principle of ITIL V3. Options A, B, and D are incorrect because ITIL V3 is not focused on Operations alone, general IT management, or Infrastructure as its core - it is specifically service-centric.