heat island rain shadow land breeze cold front
I gave my students this multiple choice question: Weather stations built in urban areas can be influenced by the human-made structures that surround these stations. Some of these weather stations used to determine mean temperatures in the United States have had the validity of the data questioned. Which human-produced effect could these urban weather stations be measuring?

Only one answer is correct among these 4 choices:
- heat island
- rain shadow
- land breeze
- cold front

Could you tell me which one is correct?

heat island