Fact 1: Hydrogen bonds cause water to expand when it freezes.

Fact 2: Hydrogen bonds Hydrogen bonds are primarily electrostatic in origin.

Given the two facts above, answer the question "Something that is primarily electrostatic in origin causes water to expand when it what?" with the following options: 
- heat
 - freezes
 - a hazard
 - boiling
 - moves
 - reacts
 - expelled
 - it's state


 

  freezes       