Evaluate the differences between IgG and IgA antibodies in terms of their structure and primary function.

• A. IgG is a monomer prevalent in blood, while IgA forms a dimer and is concentrated in mucosal areas.
• B. IgG and IgA have identical heavy chains and functions.
• C. IgG forms a pentamer, while IgA is a monomer found in blood.
• D. IgG is involved in allergic responses, while IgA is the most abundant in blood.

Answer: (A)