The correct answer is C) Simplicity of operation of the crane by its operator. Cranes offer a simpler and more efficient method of cargo handling compared to conventional cargo booms. The crane operator has direct control over the crane's movement and the positioning of the load, making the operation simpler and more straightforward. This increased simplicity of operation is a key advantage of cranes over cargo booms. While the other options (A and B) are also advantages of cranes, the simplicity of operation for the crane operator is the primary reason why C is the correct answer. Cargo booms often require more complex rigging and coordination, whereas cranes allow the operator to have more direct control over the load.