Please choose the correct answer to the question: Environments which are covered in snow are often white as a result of said snow and what other factor?

Answer1: conditions which allow little if any heat to be produced or stored Answer2: temperatures that are colder than a tropical environment Answer3: cool air that flows in a circular pattern Answer4: wind chill that meets warm fronts on occasion

Answer format: answer1/answer2/answer3/answer4
Answer: answer1