A transformation of a triangle can be either dilation or reflection or rotation or a translation.
Dilation happens when a symmetric figure is formed with scale factor other than 1. But here both triangles have same side length. Hence no dilation
Reflection happens when it is reflected over a line as we see in a mirror. But here the two triangles are not looking as images on a line. Hence no reflection
Rotation is keeping the same shape but rotating through a certain angle. Here DEF is rotated without disturbing its shape or size through a certain angle. Hence rotation is right
Translation is not right because there is no vertical or horizontal shift to get new triangle.
Correlation coefficient is the numerical representation of how one variable predicts the change of the other. In this case, if the AP tests scores and the SAT scores have 0.93 correlation coefficient, this means that the two results move in the same direction. When AP test results go up, then we can say that SAT scores will go up too, same also if one goes down, so does the other.