question: Q:Which of the following statements is correct?
  ? 
  A:The amount of oxygen available in the headspace of canned food is kept at a high level so as to limit losses of vitamin C;B:Reheating canned vegetables before serving only causes small losses of vitamin C;C:Losses of vitamin C are much higher for most canned fruits than those for canned vegetables;D:Losses of vitamin C in canned foods during storage at ambient temperature tend to be small