Ounce for ounce, blends of different artificial sweeteners match any individual

artificial sweetener in sweetening power.  When used to sweeten food, blends

greatly decrease the likelihood that consumers will exceed acceptable daily

intakes for individual sweeteners.  Blends should therefore be used, rather than

single sweeteners alone, since blends are   clearly more healthful, yet equally

effective.

 The argument depends on which of the following assumptions?

    A  When ingested together, different artificial sweeteners in the blends do not

       interact in a way that makes them harmful to human health. 

   B   Different artificial sweeteners, when used together in food, do not contribute

       a more desirable flavor to the food than would any one of them by itself. 

     C The acceptable daily intake for any given artificial sweetener is a conser-

       vative figure that could probably be greatly exceeded at little or no risk.

    D  Consumers who substitute artificial sweeteners for sugar in their diets

       generally keep track of their daily intake of different sweeteners. 

  E    The ill effects on health produced by the intake of excessive quantities of

       any single artificial sweetener cannot be reversed by reducing intake later. 

答案A