The city's new zoning laws prohibit any commercial development within 500 feet of residential areas. However, property values in some residential areas have actually decreased since the laws were enacted, despite developers seeking land further away.

✓ Correct Answer: Option D

The discrepancy is that zoning laws protecting residential areas led to decreased property values. Option D provides an alternative, detrimental factor (increased property taxes) that could directly explain the decline, overshadowing any potential positive impact of the zoning laws.