What are the causes of fever in patients returning from tropical areas?

The fever is the second most frequent cause of consultation in patients from tropical areas, after diarrhea.
Fever is a symptom of numerous infectious diseases, so it is important to know the characteristics of the patient, the geographic area, type of travel, duration, vaccination and prophylaxis, as well as accompanying symptoms.
Between 5-10% of patients are not diagnosed with the cause of fever.
It is important to recognize and be able to rule out serious diseases (malaria, typhoid fever, etc.) and those potentially transmissible (tuberculosis, viral hemorrhagic fevers, etc.).
a) Only I and II are correct.
b) Only II and III are correct.
c) Only III and IV are correct.
d) All statements are correct.