Under a construction management (cm) contract, should the cm firm's responsibilities normally begin at the construction phase, the design phase, the planning phase, or the conceptual phase?

A)-in the process of engineering design, explain the contribution of material selection. b)- explain the procedure of synthesis as is employed in engineering design. c)- is there any relationship between ergonomics and engineering design? explain. d)- safety consideration in engineering design includes human, product and the enviroment . explain how safety will be incorporated into the design?