Answer the following question: Fact 1: Operating an automobile usually requires fossil fuels. Fact 2: Fossil fuels are considered non-renewable. Given the two facts above, which activity usually requires using a non-renewable resource?

Choices:
1). decaying trees
2). fissures of hot, acidic water
3). Cutting down a tree
4). burning coal
5). deforestation
6). Drying clothes in the sun
7). Powering a wind turbine
8). Operating an automobile
Answer:
8).