A functional group is best described as reoccurring clusters of

A) elements that occur in a salt and that can neither be hydrolyzed nor dehydrated.
B) atoms that form the main reactive area for a particular compound.
C) atoms that function in the body even if temperatures and pH reach extreme values.
D) elements that form at high pH and who can successfully resist the action of buffers.
E) amino acids in a globular protein such as hemoglobin, immunoglobulins, and albumins.