This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Parasitology, Subject name: Microbiology
True about Cryptosporidium are all EXCEPT: 
Select and explain. 
A. Spores chlorine resistant, B. Add fast spores, C. Spores > 100 micro meters, D. Enzyme immune assay done
C: Spores > 100 micro meters
Answer: C: Spores > 100 micro meters 
Explanation: ANSWER: (C) Spores > 100 micro metersREF: Harrison s 18tK ed ch: 215Cryptosporidiosis is acquired by the consumption of oocystsSporozoites infect intestinal cellsparvum can spread from infected animals to humans. Since oocysts are immediately infectious when passed in feces, person-to-person transmission takes place in day-care centers and among household contacts and medical providers.Waterborne transmission (especially that of C. hominis) accounts for infections in travelers and for common- source epidemics.Oocysts are quite hardy and resist killing by routine chlorination. Both drinking water and recreational water (e.g., pools, waterslides) have been increasingly recognized as sources of infection.Clinical features:[?] Asymptomatic infections can occur in both immunocompetent and immunocompromised hosts.[?] In immunocompetent persons, symptoms develop after an incubation period of 1 week and consist principally of watery nonbloody diarrhea, sometimes in conjunction with abdominal pain, nausea, anorexia, fever, and./ or weight loss. In these hosts, the illness usually subsides after 1-2 weeks.[?] In contrast, in immunocompromised hosts (especially those with AIDS and CD4+ T cell counts <100/L), diarrhea can be chronic, persistent, and remarkably profuse, causing clinically significant fluid and electrolyte depletionDiagnosis:[?] Evaluation starts with fecal examination for small oocysts, which are smaller (4-5 micro meter in diameter) than the fecal stages of most other parasites.[?] Spores are acid fast.[?]Direct immunofluorescent stains and enzyme immunoassays can be done.[?] Cryptosporidia can also be identified by light and electron microscopy at the apical surfaces of intestinal epithelium from biopsy specimens of the small bowel and, less frequently, the large bowel.