We know that "heavy tapestry fabrics are appropriate only for use in applications that will not need to be laundered frequently."
Heavy tapestry fabric appropriate - > not laundered frequently Laundered frequently - > heavy tapestry fabric not appropriate
We also know that "these applications do not include any types of clothing...but instead include swags and balloon valances, which are types of window treatments."
C is incorrect because it states that "if heavy tapestry fabrics are appropriate for a particular application, then that application must be a window treatment." We know that these applications include types of window treatments, but there is no information in the passage to suggest that these are the only applications for which heavy tapestry fabrics would be appropriate. There are numerous other possibilities for applications which do not need to be laundered frequently.
In comparison, we know that skirts and jackets need to be laundered frequently as stated by the passage. Answer choice D uses the contrapositive to conclude that "if a fabric is appropriate for use in a skirt or jacket, then that fabric is not a heavy fabric," making D the correct answer.
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