These antibodies are IgD.
It is a monomeric antibody isotype that is expressed in the plasma membranes of immature B-lymphocytes. It is also produced in a secreted form that is found in small amounts in blood serum. IgD is co-expressed with IgM on the surface of the majority of mature B cells prior to antigenic stimulation and functions as a transmembrane antigen receptor.
B. photosynthesis
because it only occurs in plants.
Explanation:
they are all related to CO2 in a way
