Answer:
The slope is 0.
Explanation:
I'm guessing you just wanted an explanation, so here it is.
Slope is rise/run or rise over run.
So if you were to count up, you would count 0, if were to count over, you would count 4.
So you would get 0/4, but slopes must be simplified as they are basically fractions, and 0/4 = 0.
Therefore, the slope of this line has to be 0.