Final answer:
Culture is a key aspect that is learned throughout a human's life, enabling the transfer and evolution of behaviors, practices, and beliefs that define societies and contribute to global cultural diversity.
Step-by-step explanation:
When considering the key aspect of how we understand the idea of culture, one essential point is that culture is a learned behavior. Culture comprises the values, beliefs, norms, practices, language, and artifacts of society, all of which are acquired through learning processes. Unlike genetic inheritance, culture is transmitted from generation to generation through social interactions, communication, and the internalization of societal norms. As such, the correct answer to the question is that humans learn culture throughout their lives (C). This continuous process of cultural learning allows for the proliferation of cultural diversity globally and enables human beings to develop flexible responses to varied environmental and historical conditions, ultimately creating a diversity of cultures.