The "heat island" effect is caused by multiple factors including heat generated by populations, heat-retaining urban materials, and light reflection from buildings. All these elements together contribute to significant temperature increases in urban areas. Therefore, the correct answer is d. all of the above. ;
The heat island effect occurs when urban areas are significantly warmer than their rural surroundings due to several factors. These include heat generated by people, heat-retaining urban materials, and light reflection from buildings. The correct answer is D. all of the above.
;