Malaria is caused by a parasite that is transmitted by the bite of infected anopheles mosquitoes, entering the bloodstream, affecting the red blood cells. Therefore, Mosquito Dunks may be a good control of malaria in tropical countries.
On the other hand, mosquito dunk is an inappropriate control method for the other diseases listed, because <u>bubonic plague was transmitted by the fleas</u> of rats, <u>legionellosis is an infectious disease caused by a bacterium</u> (<em>Legionella</em>) that is found mainly in water bodies and <u>toxoplasmosis is caused by a parasite present in undercooked contaminated meat and the feces of cats.</u>
If you are implying one these choices not needed for survival it would be parents only when you can survive on your own (I'm not that sure but I hope this helped the slightest but)