Concept:Bilharzia, also called schistosomiasis, is caused by Schistosoma worms that spend part of their life cycle inside freshwater snails.
Explanation:The freshwater snail is the intermediate host of the parasite.
Infected snails release larvae into water, and these larvae can penetrate the skin of people who come into contact with the water.
To control the disease, the snail population must be reduced so the parasite cannot complete its life cycle.
Molluscicides are chemicals specifically used to kill snails.
Applying molluscicides in water bodies destroys the snails that harbour the parasite and breaks the transmission cycle.
Cutting low bushes around homes is a control measure for tsetse flies, not bilharzia.
Screening windows and doors with mosquito nets helps prevent mosquito-borne diseases like malaria.
Herbicides kill plants and weeds, providing no effect against snails or the bilharzia parasite.
Answer:B. Application of molluscicides in water bodies