Which document provides guidelines and expectations for IT service management?

The selection of ITIL (Information Technology Infrastructure Library) as the correct answer is based on its role as a framework that provides comprehensive guidelines and best practices for IT service management. ITIL is specifically designed to help organizations improve their IT service management capabilities, by offering a structured approach to managing IT services efficiently and effectively. It covers various aspects such as service strategy, design, transition, operation, and continual service improvement, making it the go-to resource for IT service management.

The other documents mentioned serve different purposes. For example, ISO 9001 focuses on quality management systems and ensuring that organizations meet customer and regulatory requirements, but it does not specifically address IT service management. COBIT, on the other hand, provides a framework for developing, implementing, monitoring, and improving IT governance and management practices. While it shares some overlap with IT service management, its primary focus is on governance and control rather than service delivery. Lastly, PMBOK outlines best practices in project management and does not directly pertain to IT service management practices. Each of these resources has its own focus, but ITIL stands out as the framework uniquely tailored to enhance IT service delivery and management.