Fact 1: Plants detect and respond to the daily cycle of light and darkness.

Fact 2: Potted plants in season include chrysanthemums, daisies and cyclamen.

Given the two facts above, answer the question "what detects and responds to the daily cycle of light and darkness?" with the following options: 
- chemicals
 - h2o
 - humans
 - goats
 - clouds
 - gravity
 - fens
 - daisies


 

        daisies 