Which activity ensures that new or changes products are seamlessly introduced in the live environment?

Transition is the activity that ensures new or changed products are introduced into the live environment in a controlled and seamless way, so option B is correct. In ITIL, transition bridges development and live operation. It includes planning releases, validating readiness, deploying changes, minimizing disruption, and confirming that the new or changed product can operate effectively in its target environment. Build focuses on creating or modifying solution components. Deliver is concerned with providing services to users. Operate is about maintaining and monitoring live products and systems. Transition is essential because even a well-designed and well-built product can fail if it is introduced poorly. ITIL therefore treats transition as a distinct lifecycle activity that protects service quality, reduces risk, and supports smooth adoption of changes by both technical teams and service consumers.