Q: Fact 1: Hydrogen bonds cause water to expand when it freezes. Fact 2: Water freezes into ice when cooled. Given the two facts above, what causes water to expand as it becomes ice?

Choices:
[1]. evaporation.
[2]. wind.
[3]. Weathering.
[4]. heat.
[5]. gasoline.
[6]. Generating heat.
[7]. friction.
[8]. hydrogen bonds.
A:
[8].