Final answer:
The Y-shaped molecule produced by B cells that specifically binds to an antigen is known as an antibody, a large protein that plays a key role in the body's humoral immune response.
Step-by-step explanation:
The Y-shaped molecule produced by B cells that can specifically bind to an antigen is an antibody. Antibodies are large, Y-shaped proteins that are crucial in the humoral immune response. B cells are responsible for producing antibodies after being activated by signals from other immune cells. These antibodies have antigen-binding sites that are specific to certain antigens, likened to how a key fits into a lock.
An antigen is any substance that the immune system recognizes as foreign and can elicit an immune response. Each antibody is encoded by a unique gene, allowing it to have distinct antigen-binding properties. Once a B cell encounters its specific antigen, it differentiates into plasma cells which then produce and secrete antibodies, capable of binding to the antigen whenever encountered again, and these antibodies circulate throughout the body. This process involves the formation of memory B cells and plasma cells that secrete large quantities of antibody molecules.
Therefore, the correct answer to the question is B) Antibody.