: none of all.nonnegative means (   )A:If we have a normal good, the subtitution effect and the income effect work in is nonnegative. B:If the price of a good goes up, if the good is a normal good, then it is nonnegative C:If price of good goes down, the change in the demand for the good due to the subtitution effect must be nonnegativeD:For samll changes in price, Hicks and Slutsky definitions for substitution effects are nonnegative