Fact 1: Seed dispersal has a positive impact on a plant.

Fact 2: Seed dispersal is usually by birds.

Given the two facts above, answer the question "what has a positive impact on plants" with the following options: 
- global warming
 - lack of sunlight
 - birds
 - sugar
 - warmth
 - Oak
 - growth
 - carbon monoxide


 

   birds      