As a straight line perpendicular to the ground line in both projections.
As a straight line parallel to the ground line in both projections.Correct
Like a straight line in the horizontal plane and an oblique straight line in the vertical plane.
As a straight line in the vertical plane and a straight line perpendicular to the ground line in the horizontal plane.
A plane parallel to the ground line (profile plane) is represented as two lines parallel to the ground line in its horizontal and vertical projections.