Which type of flatworms are known to infect humans?

Both beef and pork tapeworms, as well as flukes like the liver fluke, are known to infect humans, making the correct answer comprehensive. Tapeworms belong to the category of flatworms (or platyhelminths) and can be contracted through the consumption of undercooked meat from infected animals. These tapeworms can live in the human intestines, and their presence can lead to various health issues.

On the other hand, flukes are another type of flatworm and include species such as the liver fluke, which can infect humans through contaminated food or water, particularly in areas with poor sanitation. Infections caused by flukes can lead to serious conditions, such as liver damage or other digestive issues.

Considering that both categories of flatworms can lead to infections in humans, this option encompasses the full scope of the question and reflects the broader understanding of parasitic flatworms.