The boundary line is dashed or dotted. The answer is choice A.
Why is the boundary dashed or dotted? Because this tells the reader "do not include the boundary as part of the solution set". In other words, if a point is on the boundary line, then it is not a solution.
For instance, the point (0,2) satisfies x+y = 2 so it lays on the boundary line. However, note what happens when we plug (x,y) = (0,2) into the inequality x+y < 2 0+2 < 2 2 < 2 The last inequality is false. The value 2 is not smaller than itself. So that's why (0,2) is not part of the solution set. This applies to every other point on the boundary line x+y = 2.
