Fact 1: All chemical reactions require activation energy to get started.

Fact 2: Catalysts lower the activation energy.

Given the two facts above, answer the question "In what way does a catalyst help in chemical reactions?" with the following options: 
- Generating heat
 - lowered energy cost
 - metabolic reaction
 - heating liquids
 - by making heat
 - adding heat
 - increases a body's strength
 - preventing heat transfer


 

  lowered energy cost       