Concept:Endoparasites live inside the host’s body, so they are best controlled by giving medicine orally.
Explanation:Endoparasites, such as tapeworms and flukes, live in the tissues or organs of farm animals.
Drenching means forcing a liquid medicine down the animal’s throat.
This medicine travels through the digestive system and reaches the internal parasites.
The animal’s head must be raised during drenching to prevent the liquid from entering the lungs.
Dipping, dusting, and spraying are used mainly to control external parasites like ticks and lice.
Therefore, drenching is the correct method to control endoparasites.
Answer:A. drenching.