What is horizontal line used for

anything parallel to the horizon is called horizontal. As vertical is the opposite of horizontal, anything that makes a 90-degree angle (right angle) with the horizontal or the horizon is called vertical. So, the horizontal line is one that runs across from left to right

Explanation:

HOPE ITS HELPS

i would say the answer is b. zigzag lines of the leaves. i believe this is the answer because zigzag lines go in different direction while the other options like: the vertical lines of the trees, the dotted lines on the road, and the curved lines of the park benches go in one direction.