A polygon on a coordinate grid was transformed using the rule (x,y) -> (x-4,y-3). Which of these describes this transformation?
A: a translation 4 units to the left and 3 units down
B: a translation 4 units to the right and 3 units down
C: a translation 4 units to the left and 3 units up
D: a translation 4 units to the right and 3 units up