The summer of 1998 was one of the hottest summer seasons on record. Carbon dioxide gas from cars and industry is a product of burning that produces heat. Carbon dioxide in the upper atmosphere reflects heat radiated from Earth's surface. Radiation on Earth's surface is increasing because of a hole in the ozone layer
Many scientists accept the theory that excess emission of carbon dioxide from cars and industry causes a layer of gas in the upper atmosphere that traps heat. This, in turn, causes the average temperature on Earth to rise. Which of the following observations supports that theory?

Options:
- The summer of 1998 was one of the hottest summer seasons on record.
- Carbon dioxide gas from cars and industry is a product of burning that produces heat.
- Carbon dioxide in the upper atmosphere reflects heat radiated from Earth's surface.
- Radiation on Earth's surface is increasing because of a hole in the ozone layer

Carbon dioxide in the upper atmosphere reflects heat radiated from Earth's surface.