A). If you get sick, you have a weakness within the immune system that causes you to have the symptoms of the illness as the white blood cells are failing in getting rid of the illness itself.
A condition in which real or imagined fears are difficult to control is called Anxiety disorder.
The answer is "A"
Chlamidya is a STD and bacterial infection that will usually be involved with all the symptoms that you have listed.
Is this for your personal knowing or school work
I would say either Psycho-surgery, or Electroconvulsive therapy. :)