Final answer:
The pair of antibodies and their effector functions that is paired incorrectly is c: IgM . IgM is incorrectly paired with mucosal secretions, as it is typically a blood plasma pentamer and the first antibody secreted during primary immune responses; IgA is associated with mucosal secretions.
Step-by-step explanation:
A pentamer predominantly found in mucosal secretions. In fact, IgM is usually found in the blood plasma as a pentamer and it is the first antibody type that is produced and secreted by B cells during primary immune responses.
IgM can also be found as a membrane-bound monomer on the surface of naive B cells. The primary location for IgA, especially its dimeric form, is within mucosal secretions where it helps protect against pathogens in the digestive and respiratory tracts.