An elevator is an example of a mechatronic system that is designed to move vertically to carry passengers or freight between the levels of a building. In the light of your knowledge about the design and development of mechatronic products: a) Suggest at least four requirements that are needed to be considered during the design and control phases of an elevator. [4 Marks] b) Suggest the appropriate type of actuator that can be used to drive the elevator. Justify your Answer. [3 Marks] c) Mention the two popular types of hardware controllers (computer control systems) that can be used for the control task of the elevator. Which type would you choose? Justify your answer. [4 Marks]