Final answer:
The light chain rearrangement takes place at the pre-B cell stage of B cell maturation in the bone marrow, where enzymes like DNA recombinase facilitate genetic recombination of V and J segments to create a unique antibody specificity.
Step-by-step explanation:
The light chain rearrangement takes place at the pre-B cell stage. During B cell maturation, a critical process known as genetic rearrangement occurs, where enzymes like DNA recombinase randomly excises variable (V) and joining (J) segments from the light chain gene. This recombination event is essential for forming the unique variable region of the light chain which is vital for the specificity of antibody binding to antigens. Post-transcriptional modifications, or RNA processing, further refines the gene rearrangement to ensure each B cell produces a unique antibody.
Therefore, option (b) Pre-B cell is the correct answer for the stage at which light chain rearrangement takes place.
Comparison with T Cells
Like B cells, T cells also undergo genetic rearrangement for receptor specificity, but this occurs in the thymus. For B cells, the rearrangement happens in the bone marrow, and it involves the assembly of V-J segments for the light chain, and V-D-J segments for the heavy chain of the antibody.