Question

what is an antigen?
a an antigen is sticky little pieces of larger cells.
b an antigen is the large wbcs that can also swallow and destroy old and dying cells.
c an antigen is anything that can trigger an immune response.
d all of the above

Explanation:

An antigen is a substance that can trigger an immune response. Option a is incorrect as it does not accurately define an antigen. Option b describes macrophages (a type of white blood cell - WBC), not an antigen. Since a and b are wrong, d (all of the above) is also wrong.

Answer:

C. An antigen is anything that can trigger an immune response.