Step 1

Let's put 2 points on the graph. We will calculate the change in x and y using these points.

First, you 'run' to the left. This gives:

Now, you climb up. This gives:

Alternately, you can get the change in y and x by counting the number of grids.

Step 2

With the 'change in y' = 6 units and 'change in x' = -3 units, you can now calculate the slope:

Step 3

From Step 2, the slope of the line is -2. Therefore, the answer is D.