Which of the following elements is necessary for normal thyroid function?

A. Immunoglobulin G (IgG) is the most abundant antibody in the blood and plays a key role in the body's defense against bacterial and viral infections, but it is not directly involved in allergic reactions.
B. Immunoglobulin M (IgM) is the first antibody produced during an initial immune response, primarily involved in fighting infections, but it does not play a major role in allergic reactions.
C. Immunoglobulin E (IgE) is the antibody most directly involved in allergic reactions. When IgE binds to allergens, it triggers the release of histamine from mast cells, leading to the symptoms of allergies.
D. Immunoglobulin A (IgA) is primarily found in mucosal areas such as the respiratory and gastrointestinal tracts, where it helps prevent infections, but it is not directly involved in allergic responses.

A. Generating and transmitting impulses is the primary function of nervous tissue, not connective tissue. Nervous tissue is responsible for carrying signals throughout the body.

B. Covering and lining body surfaces is the function of epithelial tissue, which forms the skin and the lining of organs, not connective tissue.

C. Contracting and bringing about movement is the function of muscle tissue, not connective tissue. Muscle tissue is responsible for contraction and body movement.

D. Connective tissue's main function is to bind other tissues together and provide structural support. It includes tissues such as bone, blood, cartilage, and tendons, all of which help support, protect, and connect other tissues and organs.