Find out the correctly matched option of the causative agent and their disease.

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In modern medicine certain infectious neurological diseases were found to be transmitted by an agent consisting of abnormally folded protein. These agents were called prions. They cause bovine spongiform encephalopathy (BSE) commonly called mad cow disease in cattle. Citrus canker disease is caused by bacteria Xanthomonas citri. Cr-Jacob disease (CJD) in humans is also caused by prions. Small pox disease is caused by virus Variolla.