Which one of the following statements regarding a thermos flask is NOT correct?

• A. The walls of flask are separated by vacuum and made of glass which is a poor conductor of heat
• B. The glass walls themselves have shiny surfaces
• C. The surface of inner wall radiates a good amount of heat and the surface of the outer wall absorbs some of the heat that is radiated from the inner wall
• D. The cork supports are poor conductors of heat