Cranes can be operated only by which of the following types of persons?

Cranes are complex pieces of machinery that require a thorough understanding of operational procedures, safety protocols, and load management to operate safely and effectively. The correct choice encompasses all categories of individuals who may operate cranes:

• A qualified individual possesses the necessary knowledge, skills, and experience to perform tasks correctly and safely.

• An authorized person has been given permission by the employer to operate the crane, ensuring that their operation aligns with company policies and regulations.

• A trained person has received specific instruction in the operation of cranes, covering practical skills as well as safety measures.

Since all three aspects—qualification, authorization, and training—are essential for safe crane operation, the answer that includes "all of the above" recognizes the comprehensive requirement for a person to be capable of operating a crane proficiently and safely. Each component plays a critical role in ensuring that crane operations are conducted within legal and safety frameworks, thereby minimizing risks and accidents on the job site.