Hybridoma method for monoclonal antibodies

Steps:

• Immunize mammal with antigen to produce specific B cells.
• Harvest antibody-producing B cells from the spleen.
• Fuse spleen cells with myeloma cancer cells to create hybridomas.
• Screen hybridomas for desired antibody and culture selected clones at large scale.

Why D is correct:

• D accurately sequences the process: antigen immunization triggers response, spleen provides B cells for fusion with cancer cells, yielding immortal hybridomas producing monoclonal antibodies.

Why the others are wrong:

• A: Starts with "antibodies" instead of antigens; uses blood, not spleen, missing fusion step.
• B: Begins with "antibodies" immunization (incorrect; uses antigens); skips antigen role.
• C: Uses blood for cells (wrong source; spleen needed); omits fusion with cancer cells.

Final answer: D