What is the time complexity of the addelement operation?

Dan is a civil engineer for a company that builds nuclear power plants throughout the world. which best describes the places he works and what he does there? a) at an office analyzing blueprints, and at public meetings where safety regulations are explained b) at an office creating computer models for power plants, and at sites where the plants are constructed c) in a laboratory, where he designs power plants, and in a factory where the plants are manufactured d) in a warehouse, where he orders parts, and at sites where the parts are installed in the power plants