What does the passage mainly discuss?

Câu hỏi: Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions.
There are many different metaphors used to describe culture. My favorite one is the iceberg. I think, it demonstrates so vividly what can happen to us if we believe only in the visible and ignore or underestimate the invisible part. The hidden part of our culture is that part which we know instinctively because we absorbed it from childhood on. It's handed down to us from generation to generation. We could also say, it's the "thinking" and "feeling" part of culture: habits, assumptions, attitudes, desires, values, tastes, etc.
Now, if we are in a new culture, our customary evaluations and interpretations are likely not to be on target because we see everything through our own cultural glasses. Imagine yourself in a new city trying to get around with a map from your own hometown. It wouldn't take long for you to get lost and completely frustrated! When we experience an encounter in the new culture that puzzles us, the most common reaction is to judge it through our own cultural glasses.
I want to propose an alternate approach to our initial gut reaction. Instead of immediately and instinctively judging a situation through our own glasses, we might first just pause and notice what is happening and then realize that this is a cultural learning situation. Remember the iceberg metaphor! The new culture becomes your mirror that shows you a hidden part of your own culture. What an opportunity for personal growth and new insight! You can compare two different approaches, that of the new culture and of your own culture. This gives you a choice. Now you can decide what fits best for you or even take the best from both sides.
(Source: https://english-magazine.org/)
What does the passage mainly discuss?
A. The simplicity of culture.
B. The personal definition of culture.
C. Culture as a socializing tool.
D. The open surface of culture.