18.   which of the following pairs did not collaborate to write music and lyrics for a musical?         a. george and ira gershwin b. joplin and cohan c. rodgers and hammerstein d. bernstein and sondheim

B Joplin and Cohan is the correct answer the  rest wrote music and lyrics for the musicals

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.