What is a group of art songs unified by a story or musical ideas called?
a.) thematic transformation
b.)postlude
c.)song cycles
d.)program music

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.