Final answer:
David probably needed little training to correctly interpret his hosts' display of happiness, surprise, and sadness as revealed by their body language.
Step-by-step explanation:
c) Body language
David probably needed little training to correctly interpret his hosts' display of happiness, surprise, and sadness as revealed by their body language. Nonverbal communication, such as facial expressions and gestures, plays a crucial role in conveying emotions and cultural norms. While verbal language and written communication are also important, body language is a universal form of communication that can be understood across cultures.