David and Derek, who are visiting India together for the first time, are inclined to stereotype the locals and complain about hotels and restaurants that they feel don’t measure up to American standards. Which quality that helps develop intercultural communication competence are they most evidently lacking?

Open mindedness.

Explanation:

Open-mindedness can be defined as an ability to listen to beliefs, thoughts, and ideas that oppose one's ideas, beliefs, and thoughts. It is a characteristic that involves being receptive to others opinions as well when it contradict yours. Being open-minded helps in critical and rational thinking. Open-mindedness is also known as non-prejudiced and tolerant.

In the given case, David and Derek are Americans who are prejudiced about Indians. They are stereotype for the locals and thus complain about the services of the hotel that it does not measure the standards of American hotels. Since they are stereotyped and prejudiced, they are lacking the principle of being open-minded. That is why they complain, if they would have been open-minded they would have accepted the norms of Indian Culture.

Thus, the correct answer is open-mindedness.

who is marty in this situation?

well there are a bunch of different possibilities so your gonna have to be a bit more specific