Question

heat islands and effects
what can reduce the urban heat island effect?
additional air conditioning units
rooftops covered with plants

Explanation:

Planted rooftops (green roofs) absorb heat via vegetation and soil, reduce surface temperature, and increase evapotranspiration, which directly mitigates the urban heat island effect. Additional AC units release more waste heat, worsening the effect.

Answer:

Rooftops covered with plants