Final answer:
The correct answer is Porphyria cutanea tarda (PCT), which is associated with symptoms like dermal blisters, photosensitivity, and skin fragility, along with liver dysfunction typically seen in patients with untreated Hepatitis C.
Step-by-step explanation:
The patient with dermal blisters on the hands, photosensitivity, skin fragility, in conjunction with untreated Hepatitis C, is most likely suffering from Porphyria cutanea tarda (PCT). PCT is a type of porphyria associated with liver dysfunction, which can be exacerbated by viral infections such as hepatitis C. The presence of symptoms such as photosensitivity and blistering on sun-exposed areas of the skin is characteristic of this condition. The other options, such as pemphigus vulgaris, pemphigoid, and epidermolysis bullosa acquisita, do not commonly present with liver involvement or are less associated with hepatitis C infection.