What role must be designated by the premises owner for all hot work operations?

The correct answer highlights the importance of having a designated individual known as the "Responsible person" for hot work operations. This individual is responsible for overseeing the safety measures during the operations, ensuring compliance with regulations, and facilitating communications between the workers and other necessary personnel, such as emergency responders or fire watch staff.

By designating a Responsible person, the premises owner ensures that there is accountability and authority present during hot work activities, where sparks or heat might ignite flammable materials. This person's role includes conducting risk assessments, implementing safety precautions, and monitoring the work environment for potential fire hazards.

The other roles listed, while important in their own contexts, do not specifically align with the unique responsibilities involved in overseeing hot work operations. The Fire Marshal typically oversees fire safety regulations but may not be directly involved in every hot work instance. A Security Person focuses more on security and access control than on fire safety during hot work. A Safety Manager has a broader scope that encompasses overall safety but may not have the specific focus on fire-related risks associated with hot work operations.