Which is an achievement made in health care in the twenty-first century? A. the invention of the microscope B. the association between microbes and diseases C. development of robotic surgery D. the classification of blood into groups E. the invention of the smallpox vaccine

The answer is C because robotic surgery is a relatively new thing.

Microscopes and blood groups have been around for much longer than robotic surgery. Also, I think that we have known that microbes can cause disease since the Scientific Revolution. (What comes to mind for me is Pasteur's experiment.) Finally, the smallpox vaccine has been around since 1796.

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