Final answer:
Option (c), VJ rearrangement of the light chain occurs in the Large Pre-B stage of B cell development, facilitated by DNA recombinase, resulting in unique antigen-binding sites for B cells.
Step-by-step explanation:
VJ rearrangement of the light chain occurs in the Large Pre-B stage of B cell development. This process is essential for creating the diversity of antibodies necessary for the immune system to recognize a vast array of antigens. During this stage, an enzyme called DNA recombinase randomly excises most of the variable (V) and joining (J) segments from the light chain gene. This is followed by splicing one V segment to one J segment.
As the cell undergoes further development, this VJ rearrangement combined with RNA processing results in over 106 possible combinations, allowing each differentiated B cell to have a unique variable chain which is capable of binding a different antigen. The constant domain, which remains the same across all antibodies, does not contribute to antigen binding.