The correct answer is:
there are no exceptions, A-D are all plausible outcomes.
Explanation:
Since A to D are all plausible outcomes let me pick them one after the other and explain why each of them is a possibility.
A. You never show any symptom of the disease and there is no sign of the pathogen in your body; this is true because, when a person is newly infected with a pathogen, the pathogenic load in the person's system is very low and may just be localized and undetected but existent in the person. This is called in incubation period of the pathogen. It is essentially the period between when a person gets infected and when the first symptom of the infection is seen in the patient. After a period of nutrition, the pathogen proliferates and multiplies, overwhelming the immune system, causing whatever symptom is associated with that infection. So if diagnosis is done within the incubation period of the pathogen, it may be undetected, the patient may not show any symptom of the infection but the pathogen is residing in the patient.
B. You exhibit mild symptoms of disease and the levels of the pathogen in your body are quickly reduced and eliminated; in this case, when the pathogen invades the patient's system, and multiplies following a favorable environment, the patient comes down with mild symptoms of the disease due to the presence of toxins or other antigens produced by the pathogen. while all this is going on, the body's white blood cells called B lympocytes or B cells manufacture antibodies. during when this synthesis of antibodies is taking place, the pathogen is still proliferating so the patient feels mild symptoms but once antibodies are completely synthesized against the antigens produced by the pathogens, the pathogens are quickly eliminated and the patient returns to a normal state. Also in this case, if the pathogen re-infects the same person after antibodies have been initially produced against it, the memory cells of the while blood cell immediately re-manufactures those antibodies to tackle the pathogen, so the patient might not necessarily show even mild symptoms of the infection a second time. The person is thus said to be immunized.
C. You succumb to the worst effects of the disease but survive due to administration of antimicrobial agents; in this case, the infected person's immune system could not tackle the infection as described earlier, so the pathogen multiplies and the pathogenic effect are felt, but external agents (antimicrobial drugs) which are capable of killing the pathogen are introduced into the blood and the pathogens are killed or rendered inactive hence the patient starts to recover, also giving the immune cells more time to manufacture antibodies against the pathogen.
D. You never show any symptoms of disease, but the pathogen persists in your body; in this case, the person is called an asymptomatic carrier. Although unaffected by the pathogen, an asymptomatic carrier is capable of spreading the pathogen to another individual. The pathogen remains dormant in this individual this may be due to the fact the the body's immune system inactivates the pathogen rendering it inactive although viable, or that the pathogen enters a state of dormancy if in an unfavorable environment. many parasites do this, they encyst and remain dormant, but present.
