My guess as a non-native speaker (living in an english-speaking country) is 4, and the next best is 3. That's how I interpret the description above the answers. But the tricky part is that that the sentences are incredibly convoluted, and that the word might already have a slightly different definition for most people (like 5).
I guessed 4 as well. My take away from the passage was that despite what people think, what is often represented as heritage can be selective in nature. The clue was in the phrase "why they have been selected from the near infinity of the past".
Forget that; I'm a native English speaker, with a college degree, and I have no clue what they're looking for. Maybe 5? But that's only a guess.