What Is the Definition of the ITIL Framework

What is the definition of the ITIL framework?

A) an ISO framework that establishes a model for network management and contains guidelines for managing objects, the management database, and the application entity
B) a five-volume framework for service management that covers design, transition, and delivery of service, and from which the ISO 20000 was developed
C) a series of tools for process improvement that uses statistical methods to reduce defects in processes and manufacturing
D) a framework for enterprise architecture that provides a comprehensive approach for designing, planning, implementing, and governing an enterprise information architecture
E) a framework for enterprise IP Address Management (IPAM) based on the IANA trusted IP lease allocation scheme