"<span>a. Cultures around the world have been exposed to other cultures at a greater rate than ever before" is the best option, since globalization has made it far easier for people to be aware of other cultures and to get involved with them.</span>
Modern era has brought to the world new technologies that make people close even when they are far away in distance. These technologies also help people become aware of what's going on throughout the world.
So people from Asia, for instance, are now exposed to the Ocidental way of living, and each person, family and society choose to take some of these influences to their lives, or not.
