Why the bonsai tree makes you calm

Training and tending a bonsai tree is stress-free, rewarding hobby that does not have to be done in a hurry. Growing bonsai is a chance to relax your grip, step back and enjoy the natural beauty of plant life from the comfort of your own home.

i would think b and c

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.