Final answer:
International business and domestic business are interconnected and influence each other. D) The ability to invest abroad is influenced by the domestic economy, and international trade allows small economies to benefit from economies of scale and competition.
Step-by-step explanation:
International business and domestic business are interconnected and have a significant impact on each other. The ability to invest abroad is largely influenced by the economic vitality of the domestic market (option D). For example, a strong domestic economy with high consumer spending may lead to more investment opportunities abroad. Additionally, international trade allows even small economies to take advantage of economies of scale, as they can access a larger market and benefit from competition and the variety offered by several producers (option C).