Please answer the following question: Fact 1: Temperature changing can cause phase changes. Fact 2: Global warming is the change of the Earth's temperature. Given the two facts above, answer the question "What is an example of a phase change?" with the following options: - flow of electrons - Deoxyribonucleicacid - chemical reaction - dormant state - Global warming - It remains dormant - bullfrogs - swamp vegetation
A:
Global warming