Trace Elements Are

Trace elements are:

A) organic molecules derived from a vitamin that functions catalytically in an enzyme system.
B) inorganic molecules found in human and animal tissues in milligram per kilogram amounts or less.
C) organic micronutrients that must be supplied exogenously and are often the precursors to a metabolically derived coenzyme.
D) natural reactants,usually either a metal ion or coenzyme,required in an enzyme-catalyzed reaction.