Points (−6, 3) and (−6, −3) on the coordinate grid below show the positions of two dogs at a park:
which statement best describes the relationship between the positions of the two players?
a. dog 1's position is dog 2's position reflected across the y-axis; only the signs of the y-coordinates of dog 1 and dog 2 are different.
b. dog 1's position is dog 2's position reflected across the x-axis; only the signs of the y-coordinates of dog 1 and dog 2 are different.
c. dog 1's position is dog 2's position reflected across the x-axis; only the signs of the x-coordinates of dog 1 and dog 2 are different.
d. dog 1's position is dog 2's position reflected across the y-axis; only the signs of the x-coordinates of dog 1 and dog 2 are different.