Question

multiple choice
all of these.
an antigen is a substance that causes the body to produce antibodies.
none of these.
“antibody” is a shortened form of antitoxic (against poison) body; the body views most antigens as poison and thus produces an antibody in defense.
an antibody is a substance produced by the body in response to an antigen.

Explanation:

An antigen indeed causes the body to produce antibodies. The etymology - "antibody" being a shortened form of antitoxic body and the body seeing antigens as poison and producing antibodies in defense - is correct. Also, an antibody is produced by the body in response to an antigen. So all the non - "None of these" statements are correct.

Answer:

All of these.