The Addition and Subtraction of Nucleotides at the Junctions Between

The addition and subtraction of nucleotides at the junctions between V, D, and J gene segments creates antibody proteins with wide variations in the numbers of amino acids in their CDR3 regions. This variability in CDR3 length is important as:

A) Overall variability in CDR3 sequence is needed to create a sufficiently diverse antibody repertoire.
B) The CDR3 region is more important in binding antigen than the CDR1 and CDR2 regions are.
C) Some light chains bind better to heavy chains with longer CDR3 region sequences.
D) Longer CDR3 sequences generally create antibodies with higher affinity for the antigen.
E) Some antibodies bind relatively flat surfaces and others bind deep clefts in the antigen.