A survey taken ten years ago of residents of area L showed that although living conditions were slightly below their country' s average, most residents of L reported general satisfaction with their living conditions. However, this year the same survey found that while living conditions are now about the same as the national average, most residents of L report general dissatisfaction with their living conditions. Which one of the following, if true, would most help to resolve the apparent conflict between the results of the surveys described above?
A: Ten years ago the residents of area L were not aware that their living conditions were below the national average.
B: Living conditions in an area generally improve only if residents perceive their situation as somehow in need of improvement.
C: Optimal living conditions were established in the survey by taking into account governmental policies and public demands on three continents.
D: Between the times that the two surveys were conducted, the average living conditions in L's country had substantially declined.
Choose A, B, C or D as your solution.
D