Please answer the following question: Fact 1: Some animals' fur grows thicker for staying warm in the winter. Fact 2: Fur seals grow a thick undercoat of fur, used as insulation. Given the two facts above, answer the question "What stays warm in winter?" with the following options: - bushes - snakes - fur seals - lizards - Conifers - bullfrogs - some mammals - fish
Answer:
fur seals