The answer here is B they are each made of matter. some are compounds, and some are elements they all contain Atoms this is because Silver and Oxygen are elements while Carbon Dioxide and Water are compounds. Although you do not have the choices down, I have come across this question before.
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Your question: What 19th century major development came about as a result of physicians’ understanding that microorganisms caused disease?
Your answer: Infection control was the 19th century development that came about as a result of physicians' understanding that microorganisms caused diseases.
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