Question

Which of the following is true when graphing inequalities in two variables?
A: just one point is insufficient to verify whether the region is a solution set or not
B: the line corresponding to the inequality belongs to the solution set only if the inequality is of the ≤ or the ≥ type
C: if the inequality is of the < or the ≤ type, then the solution set must lie below the x-axis
D: if the inequality is of the ≤ or the ≥ (less than or greater than), then two distinct regions exist in the solution set