Which of the following step is included in food canning by sterilization, which is considered the ideal method for food canning?

• A. Sterilization by heating and cooling by a tubular heat exchanger
• B. Sterilization of containers and covers with super heated steam
• C. Filling of sterile product into the sterile container, application of sterile covers to filled containers and sealing cans in an atmosphere of either saturated or super heated steam
• D. All of the mentioned