A 5-year-old white male has an itchy lesion on his right foot. He often plays barefoot in a city park that is subject to frequent flooding. The lesion is located dorsally between the web of his right third and fourth toes, and extends toward the ankle. It measures approximately 3 cm in length, is erythematous, and has a serpiginous track. The remainder of his examination is within normal limits. Which one of the following is the most likely cause of these findings? (check one)
A. Dog or cat hookworm (Ancylostoma species)
B. Dog or other canid tapeworm (Echinococcus granulosus)
C. Cat protozoa (Toxoplasma gondii)
D. Dog or cat roundworm (Toxocara canis or T. mystax)