Q: Fact 1: Gases released during the use of fossil fuels causes global warming. Fact 2: Oil is a fossil fuel. Given the two facts above, gases released during the use of oil causes what?

Pick from: 1). global warming; 2). better weather on the earth; 3). colder weather; 4). less oily air; 5). The atmosphere; 6). flooding; 7). Temperature; 8). cleaner air to breathe;
The answer is:
1).