In which condition can annual comparison of density give a wrong conclusion?

Correct answer: When area boundary changed and it is ignored

Direct answer: Option A is correct. Population density is calculated by relating population to area, commonly as population per unit of area. If the boundary of a district, town or other reporting unit changes between two years and the change is ignored, the population and area may no longer refer to comparable places. The apparent rise or fall may then reflect a boundary adjustment rather than a real demographic change. Option B supports a fair comparison because the same area and method are used. Option C improves accuracy rather than causing an error. Option D also prevents confusion by making the measurement unit clear. Before comparing annual density, check the boundary, area, population source, date and calculation method. Memory cue: compare like with like; a changed boundary can change the result even when settlement patterns have not changed.