Fact 1: High temperatures can cause an object to combust. Fact 2: And combustion equals power. Given the two facts above, what can cause a more powerful reaction?

OPT:
1). heating liquids.
2). hyperthyroidism.
3). Thyroid-stimulating hormone.
4). hypothyroidism.
5). chemical reaction.
6). higher temperature.
7). energy of moving objects.
8). heat energy.
Answer:
6).