Which line is parallel to the horizon?

Which line is parallel to the horizon?

• A. Convex
• B. Vertical
• C. Diagonal
• D. Horizontal

Answer: (D)

Lines parallel to the horizon have a horizontal orientation, meaning they run left to right and stay at the same height across the image. The horizon serves as a horizontal reference, so any line that doesn’t tilt up or down matches that direction. Vertical lines go up and down, not across. Diagonal lines tilt, moving upward or downward as you move along them. Convex describes a shape’s curvature, not its direction, so it doesn’t indicate horizontal alignment. Therefore, the line that is horizontal is parallel to the horizon.

Lines parallel to the horizon have a horizontal orientation, meaning they run left to right and stay at the same height across the image. The horizon serves as a horizontal reference, so any line that doesn’t tilt up or down matches that direction. Vertical lines go up and down, not across. Diagonal lines tilt, moving upward or downward as you move along them. Convex describes a shape’s curvature, not its direction, so it doesn’t indicate horizontal alignment. Therefore, the line that is horizontal is parallel to the horizon.