If an area's area appears increased but the new area is uninhabited desert, which caution about average density is correct?

Correct answer: Average density may understate real settlement pressure

Direct answer: Option A. Average population density is calculated by dividing total population by total area. If uninhabited desert is added, the population may remain unchanged while the area becomes larger. The denominator increases, so the average density can fall. However, people may still be concentrated in the older settled part, where homes, roads, water and jobs continue to face pressure. Thus, the average for the whole area may make settlement pressure look smaller than it really is in inhabited places. Option B is wrong because density does not always increase; it can decrease when area grows without population growth. Option C is wrong because adding land does not add people. Option D is wrong because area is a key part of the density formula. A useful memory cue is: same people plus more empty land usually means lower average density, not lower pressure in crowded settlements.