Answ
Left - antigen
Top Right - antibody
Bottom right - B cell
Explanation:
Antibodies (top right label) are Y shaped proteins involved in the detection of pathogens. They specifically detect molecules associated with pathogens called antigens (left).
Antibodies are produced by B cells (bottom right) which are a specialised class of immune cells that make up part of the adaptive immune system. B cells are often referred to as white blood cells.
