D. y = 9 because it has a complete zero slope while the y-intercept of the equation is 9, so the equation is y = 9.
Answer:

Step-by-step explanation:
Since the <em>rate</em><em> </em><em>of change</em><em> </em>[<em>slope</em>] is zero, that automatically makes our equation set equal to the y-coordinate of the ordered pair, which in this case is the y-intercept.
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