Final answer:
An immature B cell is expected to have both IgM and Igα & Igβ on its surface. These molecules are essential for the B cell's antigen binding capability, which leads to its activation and subsequent immune response involvement.
Step-by-step explanation:
An immature B cell is expected to have IgM and Igα & Igβ on its surface. Immature B cells, or naive B cells, express membrane-bound IgM as their B-cell receptor (BCR) with Igα and Igβ acting as signaling components. As the B cell matures, it may also express IgD on its surface, which works with IgM to mediate initial immune responses. The presence of these immunoglobulins on the surface indicates that the B cell is ready for antigen binding and subsequent activation. These molecules are critical for the B cell's role in the adaptive immune response.
IgM, initially produced in a monomeric form, is the antigen-binding receptor on B cells. It binds antigens non-specifically and presents them to helper T cells in the context of the major histocompatibility complex-II. This interaction stimulates B cell differentiation into plasma cells through a process that involves DNA rearrangements. The immature B cell will not express IgD with a surrogate light chain, nor will it express IgA. Therefore, the correct answer to the provided question is a. IgM and Igα & Igβ on its surface.