When a tapeworm steals nutrients from the gut of a mammalian host, that symbiosis is called?

Tapeworms are known to feed off of their hosts to complete their life cycle. This type of symbiotic relationship is called parasitism. Parasitism is defined as the type of symbiotic relationship wherein only one of the two interacting organisms benefit, at the latter organism's expense. Parasites could either be found inside or outside the host's body. Tapeworms are internal parasites. 

The correct answer is b