Two similar triangles below are shown on the coordinate grid:

Which set of transformations has been performed on triangle MNO to form triangle M′N′O′? Dilation by a scale factor of 2 followed by reflection across the x-axis Dilation by a scale factor of fraction 1 over 2 followed by reflection across the x-axis Dilation by a scale factor of 2 followed by reflection across the y-axis Dilation by a scale factor of fraction 1 over 2 followed by reflection across the y-axis