Moalem's Survival of the Sickest Practice Test

The key idea is that the parasite engineers the host’s behavior to promote its own transmission. The Guinea Worm causes a painful burning blister, and the host seeks relief by placing the affected area in cool water. That immersion in water is exactly what the worm relies on: it bursts through the skin and releases larvae into the water, where they can be eaten by copepods and continue the life cycle. So this manipulation—driving the host to submerge the lesion in water to relieve pain—facilitates transmission. The other options don’t align with how the worm’s larvae enter water and continue the cycle, so they don’t fit as the parasite’s manipulative strategy.