What is the primary cell type involved in humoral immunity? what is the primary cell type involved in humoral immunity? macrophagesb cellsinterferonsnatural killer cells?

The correct answer is B cells.

Humoral immunity is a type of immunity which is mediated by antibodies (immunoglobulins IgA, IgB, and IgM) in extracellular fluids secreted by B cells. B cells recognize antigens or pathogens that are circulating in the lymph or blood and have a role to neutralize it or eliminate it.

The primary type of cell involved in humoral immunity is the B-cell. 
Humoral immunity is a type of immunity of the adaptive immune defenses that is mediated by the antibodies secreted by B lymphocytes or the B-cells. Antigen that binds to the B-cell antigen receptor signals B cell and is at the same time internalized and processed into peptides that activate armed helper T cells. Then the signals from the bound antigen and the helper T cells stimulate the B cell to secrete specific antibody which then protect the host cell.