Which Statement Is True About SPPS

Which statement is true about SPPS:

A) In SPPS the carboxy terminus of the peptide is covalently linked to the resin.
B) The next amino acid is coupled to the N- terminus of the growing peptide.
C) The carboxylic group of the amino acid to be added to the growing peptide is activated by using dicyclohexylcarbodiimide (DCC)
D) SPPS is used to synthesize up to 100-amino acid long peptides.
E) all of the above