Cephalization Is Clearly Adaptive for the Free-Living Planarians That Must

Cephalization is clearly adaptive for the free-living planarians that must locate their food; why would the parasitic flukes and tapeworms retain cephalization?

A) Withal parasites have separate sexes and need to locate the appropriate gender when mating.
B) Parasites require a living, metabolizing host; if the parasite detects illness or the death of the host, it will seek out a healthy individual.
C) Most infections begin by ingesting the parasite; having a head allows the parasite to orient its body before being swallowed.
D) Parasitic infection is typically organ or tissue specific; parasites need to sense their location before attaching to or penetrating a body structure.