Final answer:
Technology and globalization have had the most significant impact on redefining managers' responsibilities in the hospitality industry by broadening competition and necessitating adaptation to a tech-driven, global market.
Step-by-step explanation:
Among the factors listed, the greatest impact on redefining the responsibilities of managers in the hospitality industry is likely due to advancements in technology and the globalization of the hospitality market. The intertwined nature of these two shifts has completely transformed how we define markets in the modern business landscape. Improved communication technologies, such as the internet, have allowed customers to engage with businesses from all over the world, thus increasing the degree of competition that local businesses face. Similarly, the hospitality industry has seen its market expand globally, with business-to-business websites facilitating interactions between suppliers and buyers across international borders, enlarging the competitive field and promoting the necessity for managers to adapt to a more interconnected, technology-driven environment.