Correct Answer: D
Explanation: The function turtle.color(0,0,0) can change the colour of the arrow. The function turtle.color(0,1,0) will make the arrow green. The function turtle.color(1,0,0) will make the arrow red. The function turtle.color(0,0,1) will make the arrow blue. The function turtle.color(0,0,0) will make the arrow black.