Answer:
 Option B
Explanation:
To check the system of inequalities we will take a point in the shaded area of the graph.
Then we will plug in the coordinates in the inequalities to check the validity of the inequality.
Let a point in the shaded area is ( 0,1)
Option A ⇒ y < 3x - 1 
 1 < 3 × 0 - 1
 1 < -1
 False. So this graph is not for this system.
Option B ⇒ y > 3x - 1
 1 > 3 ×0 - 1
 1 > -1
 x + 3y < 6
 0 + 3 × 1 < 6
 3 < 6
 Valid for both the inequalities so the system graphed is the set of y > 3x - 1 and x + 3y < 6
Option C ⇒ y ≤ 3x - 1
 1 ≤ 3 × 0 - 1
 1 ≤ -1
 Not valid
Option D ⇒ y ≥ 3x - 1
 1 ≥ 3 × 0 -1
 1 ≥ -1
 Since 1 ≠ -1
So this point is not in the shaded area.
Therefore, Option B is the answer.