If I have a A+ and make a bad grade on a quiz that's worth only 10% of my grade, will it affect it a whole lot or just a little?

The establishment of columbia as the state capital was important because a) it was located in the heart of the upcountry. b) it was located in the heart of the low-country. c) it was already established as a vital industrial center. d) it represented a compromise location central to most citizens.