The Distribution of Amino Acids in a Protein Often Cannot

The distribution of amino acids in a protein often cannot be determined precisely by acid hydrolysis.Why?

A) The side chains of asparagine and glutamine are also hydrolyzed.
B) The amine groups on lysine and arginine neutralize much of the acid.
C) The side chain of phenylalanine is almost totally destroyed by acid hydrolysis.
D) All of the above.