You are presented with the question "What is called when plants grow toward the sun or an artificial light?" and the following answer choices: 
- Exfoliation
 - Brownian motion
 - heat energy
 - phototropism
 - photovoltaic
 - autumn
 - peachleaf willow
 - mitosis

Now knowing that plants exhibit phototropism, or growing toward a light source and many light sources such as the sun and most artificial lights produce unpolarized light, choose the best answer.


 

    phototropism     