The correct answer is antigens and epitope.
An antigen is a substance which triggers an immune response in an organism. This can be either a foreign substance, such as a pathogen, or a specific part of the host organism (in this case this is an autoimmune response). The presence of an antigen activates a specific part of the immune system, called antibody. Each antigen has a specific antibody, which is tailored by the immune system accordingly. More specifically, the antibody has a specific structure, called paratope, which is complementary and binds like a key to a specific structure of the antigen, called epitope.
Right upper is the location for the duodenum
A basic definition of an ionic compound is that they are molecules that consist of charged ions. These ions have opposite (both negative and positive) charges. On the other hand, covalent compounds are non-metals which are bound together, and consist of two electrons that are shared between two atoms.
Answer: I think the answer is c
Explanation: