Answer:
Its the first option.
Explanation:
y = 3x - 9 on the boundary.
Any points on this line must satisfy this equation.
Try (0, -9) and (3,0):-
-9 = 3(0) - 9 = -9 so the first point is on the boundary.
(3, 0):
0 = 3(3) - 9
= 9 -9 = 0 so this point is on the line also.