Q: Fact 1: Glass cause refraction of light. Fact 2: Mirrors are plate glass. Given the two facts above, mirrors cause?

Possible answers:
1). heat energy;
2). direct energy;
3). depletion of light;
4). inspection of light;
5). flow of electrons;
6). refraction of light;
7). optical illusions;
8). The area was once underwater;
The answer is:
6).