Doxycycline can be used for the prevention of malaria.
Doxycycline, have been proven to keep rosacea's bacterial component under control and also seem to have an anti-inflammatory benefit.
Anthrax can be treated with doxycycline.
I believe your answer would be D, because Doxycycline ca help prevent the others but not Bronchiectasis.
I really hope this helps, and if not then i'm so sorry, and good luck. Let me know if my answer was correct or not. If you need any more help i'd be glade to help you.
