A.) Mark is correct as every increase in x of 2 equals a y increase of 4
Translation in right or left causes the x coordinate to change while translation in up or down causes the y coordinate to change.
Moving left or down causes the coordinates to be going negative.
Moving right or up causes the coordinates to be positive.
Original point (10, 1).
Down 1 unit:
(10, 1 - 1) = (10, 0)
Left 7 units:
(10 - 7, 0) = (3, 0)
You end at (3, 0)
+ 
or x = -