How is the following compare-and-contrast essay organized?

football means different things to people in different countries. for americans, it is a game with set plays that are designed to march an oblong ball down the field in a near-military fashion. for much of the rest of the world, football, or soccer, is a display of free-flowing action where a round ball is in constant motion up and down the field.

a.
by chronological order

b.
point by point

c.
subject by subject

d.
by order of importance