A dilation means that a shape is expanded or shrunk by a scale factor. The scale factor is 4, so all the points are multiplied by 4 to reflect this expansion.
A reflection over the y-axis means that the y-values in the points change their sign from positive to negative, and vice versa.
Therefore, the points will become the following: A''(12,-12), B''(-4, -12), C''(-16,-4), D''(0, -4)
This new shape will be similar to the original shape, since it shares the same shape, but not the same size.