An astronomical instrument known as the astrolabe was perfected by which culture?

Well based on my knowledge the Astrolabe was perfected by the Spanish and played a significant role in Columbus' and the other early travellers' journey to the West but it can be argued that it was the Muslims (Arab) that introduced it to Europe

Yes all of them are right

Americans often speak of their country as one of several large regions.  these regions are cultural units rather than governmental units --  formed by history and geography and shaped by the economics, literature and folkways that all the parts of a region share. what makes one region different from another? a region's multicultural heritage as well as distinct demographic characteristics like age and occupation make regions different and special. within several regions, language is used differently and there are strong dialects. there are also differences in outlook and attitude based on geography.