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We have the area of the rectangular prism=270 in^2

Consider the length =BD

Width=AB=15in

Now,Area=length*Width

270=15*BD

BD=18 inch

Now when the rectangle is rotated about the line connecting CF then the it will descibe a cylindrical surface whose base will have a radius =BD/2= 18/2 in=9 in

answer --option C

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