Final answer:
Scabies is the highly contagious disorder caused by a parasite, specifically the itch mite Sarcoptes scabiei var. hominis. (option c)
Step-by-step explanation:
The highly contagious disorder caused by a parasite is Scabies. Scabies is an infestation of the skin by the human itch mite Sarcoptes scabiei var. hominis. This microscopic mite burrows into the upper layer of the skin where it lives and lays its eggs. The most common symptoms of scabies are intense itching and a pimple-like skin rash. The scabies mite usually is spread by direct, prolonged, skin-to-skin contact with a person who has scabies.
On the other hand, Impetigo is caused by bacteria (Staphylococcus aureus or Streptococcus pyogenes), not parasites, and presents as blisters or sores on the skin. Eczema is an inflammatory condition that is not caused by a parasite, and Psoriasis is a chronic autoimmune condition that results in the overproduction of skin cells.
Therefore, the correct answer is C) Scabies.