The first line passes through the points (0,6) and (6,0).
The second line passes through the points (6,5) and (0,-1)
The point of intersection is shown in the graph.
The point is 3 units right and 3 units above the origin.
Since it is 3 units right the x-co ordinate is 3
Since it is 3 units above the origin the y- co ordinate is 3.
Hence the point of intersection is (3,3).

Option D is correct.