1. The problem asks to select the correct rephrased statement for Rebecca's proof that if the diagonals in a parallelogram are perpendicular, then it is a rhombus. 2. Recall the definitions: - A parallelogram has opposite sides parallel: $AB \parallel DC$ and $AD \parallel BC$. - A rhombus is a parallelogram with all sides equal: $AB = BC = CD = DA$. - The diagonals of a rhombus are perpendicular: $AC \perp BD$. 3. The statement to prove is: "If the diagonals in a parallelogram are perpendicular, then it is a rhombus." 4. This means starting with a parallelogram ($AB \parallel DC$ and $AD \parallel BC$) and the condition $AC \perp BD$, then concluding $AB = BC = CD = DA$. 5. Among the options, the correct rephrased statement is: "In quadrilateral ABCD, if $AB \parallel DC$, $AD \parallel BC$, and $AC \perp BD$, then $AB = BC = CD = DA$." This matches the logical flow of the proof. Final answer: In quadrilateral ABCD, if $AB \parallel DC$, $AD \parallel BC$, and $AC \perp BD$, then $AB = BC = CD = DA$.