Final answer:
The correct translation rule for moving triangle ABC 2 units to the right and 3 units down is described by the function (x+2, y-3), corresponding to option B.
Step-by-step explanation:
The question concerns a translation of triangle ABC in a coordinate plane. Triangle ABC has been translated 2 units to the right and 3 units down. To describe this translation mathematically, we need to update the coordinates of each point in triangle ABC by adding 2 to the x-coordinate and subtracting 3 from the y-coordinate of each point. The correct rule for this translation is represented by the function (x+2, y-3), which takes a point (x,y) and transforms it to a new point (x+2, y-3).
Therefore, the correct option among the choices given is B (x+2, y-3).