Which stage of the life cycle of the tapeworm is harbored in the intermediate host?

The larval stage of the tapeworm is the correct answer as it represents the developmental form that resides within the intermediate host. In the life cycle of tapeworms, the adult stage is typically found in the definitive host, where it can reproduce and produce eggs. The intermediate host is crucial for the larval form's development, which usually occurs after the ingesting of eggs or cysts.

During this stage, the larva often undergoes significant transformations, enabling it to adapt to the intermediate host's environment. These transformations are essential for the survival of the larval form until it can be transmitted to the definitive host.

The egg stage is produced by the adult in the definitive host and is typically laid in the environment or consumed by the intermediate host, rather than being present in the intermediate host itself. The proglottid stage refers to segments of the adult tapeworm that contain reproductive structures and can also be found in the definitive host, not in the intermediate host. Hence, the larval stage's presence in the intermediate host is a key aspect of the tapeworm life cycle, facilitating its propagation and survival.