<prompt> Bacterial spores are hest destroyed by-UV raysAutoclaving at 121degC for 20 mintsHot air OvenInfrared rays  <response>: Ans. is b i.e., Autoclaving at 121degc for 20 minutes Autoclaving . Autoclaving is a method to sterilize equipment by subjecting them to high pressure at 121degC or more. . It is sterilization by steam under pressure. . The device which is used for autoclaving is known as autoclave. 