Q2: Answer: B
This is likely a tapeworm infection with Diphyllobothrium latum, and most tapeworm infections are treated with praziquantel. D. latum infection can be acquired by ingesting certain forms of freshwater fish, and those who consume raw fish, including sushi, are at increased risk. Patients infected with D. latum may develop a megaloblastic anemia secondary to vitamin B12 deficiency given that D. latum competitively interferes with normal host absorption. All the other agents listed would not be used for treatment of tapeworm infection.
Reference
1. Scholz T., et al. Update on the human broad tapeworm (genus Diphyllobothrium), including clinical relevance. Clin Microbiol Rev. 2009;22:146-60.