Chords built with the interval of thirds is sometimes called:
O tertian harmony
dissonant harmony
subordinate harmony
coordinate harmony

Tertian harmony is a harmony built on an interval of thirds.

melody. a series of single tones which add up to a recognizable whole is called a what kind of layers of sound are heard melody or harmony. how many layers

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.