They weren't as accurate as they could be, in fact some were just based off of educated guesses.
Answer: Thermal inversion
Explanation: Thermal inversion or change the position of the air layer, when the warmer layer of air is above the cold layer, which is usually not the case. It happens due to a change in the normal temperature gradient, i.e. when the gradient becomes inverted. Such thermal inversions can occur in oceanic areas with a lot of upwelling near the coasts. Thermal inversion also occurs when sun radiation is less than radiation from the earth, which is the case during the night. The significance of these inversions is great, especially for air quality in polluted environments such as urban. The strongest inversions are during the winter and can then be dangerous due to poor air quality, which is measured by the AQI (Air Quality Index). The higher the AQI index, the greater the risk of bad air, that is, the worse air.
The answer is C. Hope this helped
You would take a ruler and measure the amount of centimeter or inches between the two places. Then measure the scale. If the scale was 50 miles and 1 inch and the two points were 2 inches apart. The places would be 100 miles apart because 50*2=100
