The correct answer is "early in b cell development, recombinase links one light-chain v gene segment to one j gene segment".
Recombinase is an enzyme whose function is genetic recombination. There are many different types of recombinase and one of these is the V(D)J recombination. This is a recombination occurring in developing lymphocytes during the beginning of the maturation of T and B cells. V(D)J recombination involves somatic recombination and its basis is the random rearrangement of variable (V), joining (J) and diversity (D) gene segments. This process ensures the lymphocyte diversity seen in all the different types of antibodies and T cell receptors found on B and T cells.