Which of the following is not one of the ITIL core publications?

ITIL is the abbreviation for Information Technology Infrastructure Library. It focuses on managing informational technology. ITIL helps businesses because they take what they have and modify it to fit the business and the needs of the business. Their service design includes coordinating the design, managing the service catalog, managing the service level, availability management, capacity management, allowing management for information technology service on a continuing basis, managing security of your technology and supplying the management.

Each of these things has specific functions and jobs that it does. For example, IT service continuity management providing assessment for the risk the business has regarding threats and other problems experienced in technology. Service optimization is not a job or task that is not included in the ITIL core publications.