A 34 year-old male comes to your office with fever, chills, headache, fatigue, myalgias, arthralgia, anorexia, nausea, sweats,and depression. He returned from a hunting trip after spending two weeks in St.Paul, Minnesota. His past medication history is significant for splenectomy after a motor vehicle accident four years ago. Physical examination is significant for tenderness in the right upper quadrant. Laboratory tests showed anemia, thrombocytopenia, elevated transaminases and intraerythrocytic ring-shaped parasites in tetrads on Giemsa-stained blood smears and later confirmed by a PCR assay which showed the DNA of the organism. You suspect babesiosis in this patient. Of the following which organism carries Babesia microbial, the organism responsible for Babesiosis?
