Which statement best describes multinational firms?

a$.$

Multinationals are defined as companies heavily engaged in exporting and importing.

b$.$

Multinationals often develop their global businesses in stages.

c$.$

Multinationals typically do not change their methods of reaching their global markets if they are successful with their initial strategy.

d$.$

All multinationals must enter the fourth stage of globalization before they are fully internationalized.