To solve this you need to get x by itself, so to do this you simply subtract 3 from each side of the equation making it...
x >= -4
The arrow points to the right meanings that on the graph the arrow will go towards the right.
You could also think about it that x is greater than or equal to -4, so the arrow will be going towards the positive numbers from -4 meaning the arrow will go towards the right.
Also since it is greater than or equal to the circle will be a solid, filled in circle.
D is the answer
Hope this helps!