The answer to this question is all of the above. Why? Well, see below for an explanation!
It is important to dress in layers during the winter because first off, snow is liquid but is maintained in a solid and fluffy state due to low temperatures. That being said, the snow can melt in your hands or anywhere on your body if you do not wear the appropriate clothing. Layering down in clothing while it is wintertime can prevent snow from getting your body wet. It is also important to dress down in layers during wintertime because layers of clothing trap your body’s heat. All humans’ bodies give off internal heat and when you dress in layers, that heat is sustained within your clothing so you stay warm. Lastly, layering your clothing during wintertime can help prevent frostbite and hypothermia. Frostbite is a condition that is most common during the winter where your skin and its tissue freeze. If any of your body parts are exposed, it is likely that you could get frostbite. Hypothermia is a dangerous condition in which your body temperature significantly drops. If this continually happens without any treatment or address of the situation, you could potentially freeze to death.
Your final answer: Because all of these answers have correct explanations for why it is important to dress in layers during wintertime, your answer is “all of the above.” If you need help, let me know and I will gladly assist you.