Which of the following is a constituent of antigen?

Both A and C.

a- Protein.

b- Diglycerides.

c- Glycoprotein.

d- Both A and C is the correct option .

 Any substance that causes the body to make an immune response against that substance. Antigens include toxins, chemicals, bacteria, viruses, or other substances that come from outside the body. Body tissues and cells, including cancer cells, also have antigens on them that can cause an immune response. An antigen is a substance that can trigger an immune response in the body. It is typically a molecule recognized by the immune system, and it can include various types of molecules. In this case, proteins (option A) and glycoproteins (option C) are both constituents of antigens.

A glycoprotein is a protein molecule that has carbohydrates (sugar molecules) attached to it. Many antigens are glycoproteins, and these carbohydrate moieties can play a role in the immune system's recognition and response to the antigen. Therefore, both protein and glycoprotein are constituents of antigens.