Hi, since this is a QC question shouldn’t we be skeptical about the diagonal dividing the rectangle into two triangles ? Only if the rectangle is a square then it divides the 90 degree angle as 45, 45. So my question is when can we safely assume that when a diagonal is drawn across a rectangle it divides each side angle into 45, 45.

I thought the answer would be (D) here since we are not sure if the rectangle is a square.