Answer: Parasitism
Step-by-step explanation:
You didn't give the options and I couldn't get them online but based on the information given, the relationship is parasitism.
Parasitism is a refered to as a symbiotic relationship that exists between organisms such one organism, which is known as the parasite, either lives on the other organism which is called the host or lives inside it and causes the host harm.
In this case, the parasite benefits at the expense of the host. Examples of parasites include tick, fleas and tapeworms.
With regards to the question, the tapeworm causes people harm and benefits at the expense of its host.