Which of these was an experimental type of Romanesque architecture? a. ribbed domes b. ribbed arches c. ribbed vaults d. all of the above

It's C. ribbed vaults

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.