Correct Response: D. Housing costs vary significantly in different geographic areas. For example, housing costs in metropolitan areas are generally higher than in rural areas. Housing costs can also vary significantly within the same area, neighborhood by neighborhood. Transportation expenses contribute to the cost of living, but the variation in costs is not as significant as for housing (A). Food costs fluctuate, but the change is not as substantial as housing costs (B). Health care costs also vary, but not nearly as much as housing costs (C).