What fly lays eggs in the soil and has larvae that burrow into the bodies of earthworms?

The correct choice identifies the cluster fly, which is known for its unique life cycle that includes laying eggs in soil. Once the eggs hatch, the larvae emerge and seek out hosts, specifically targeting earthworms. Upon locating the worm, the larvae burrow into its body, continuing their development within the host.

This lifecycle is a distinct characteristic of cluster flies, differentiating them from the other types mentioned. For instance, flesh flies and screw worm flies are typically associated with decaying matter or animal carcasses, and house flies are more associated with waste and decaying food sources. The ecological role of cluster flies as parasites of earthworms highlights their particular adaptation and niche within the ecosystem, making this choice the most accurate in relation to the lifecycle described in the question.