A personality can be caused by a difference in

People vary in personality and social behaviour. It is generally accepted that some of this variation is due to differences in genes and some to “environment”—that is, to differences in people's experiences. This chapter is about the latter source of individual differences, the variation that is not due to genes.

do you mean putto's   i think they are easier to draw..

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.