Answer :
I believe the correct answer is A. temperature readings that have a range of 2°C depth. This should be correct because 2 degrees is a small number, meaning that there isn't much space for mistakes here. However, the other options provide larger numbers, such as 4 km, 20%, and 40 kg/L, which is obviously much larger than 2 degrees, which means the results won't be as precise and accurate.