This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacteria, Subject name: Microbiology
Weil's disease is caused by? 
Select and explain. 
A. Leptospira, B. Plague, C. Yersinia, D. Rickettsial fever
A: Leptospira
Answer: A: Leptospira 
Explanation: ANSWER: (A) LeptospiraREF: Jawetz's 24th ed chapter 25Leptospira icterohaemorrhagiaeSource of Infection - Rat urine, waterDisease in Humans - Weil's diseaseClinical Findings - Jaundice, hemorrhages, aseptic meningitisLeptospirosis is also known as Weil's disease, Weil's syndrome, canicola fever, canefield fever, nanukayami fever, 7-day fever, Rat Catcher's Yellows, Fort Bragg fever, and Pretibial feverClassicactivationpathwayAntigerif'antftxxfy immune complexClq-C1r-C1sMannose-bindinglectinactivation pathwayMicrobes with terminal manose groupsMBL-MASP1 -MASP2AlternativeactivationpathwayBacteria, fungi, vims, or tumor celtsC3 (H2O)