Which of the following is not responsible for the urban heating effect?
a. increased reflected sun energy of urban environments relative to that of natural landscapes
b. heat generated by homes, vehicles, and factories
c. the concentration of people, machines and heat generating devices adds more heat to the environment
d. increase in human-made materials that conduct more energy than natural surfaces

The correct option is letter A: Increased reflected sun energy of urban environments relative to that of natural landscapes

Explanation:

Option A is the perfect example of the result of urban heating and not a cause of it. The responsible is the man simply because we create urban environments that are not eco-friendly and this increases the reflected solar energy, therefore increases the heat. So, again, the increase of the heat would be the result.