For one person to produce over a million different antibody molecules, could not possibly require over a milli

For one person to produce over a million different antibody molecules, could not possibly require over a million different genes. Instead, this variability is accounted for by which process?

A) Alternative splicing of exons after transcription.
B) Increased rate of mutation in the RNA molecules.
C) DNA rearrangements followed by alternative splicing.
D) DNA rearrangements in the thymus.
E) Crossing-over between light and heavy chains during meiosis.

C) DNA rearrangements followed by alternative splicing.