Fact 1: Cross-pollination increases genetic diversity.

Fact 2: Biodiversity is basically genetic diversity.

Given the two facts above, answer the question "What increases biodiversity?" with the following options: 
- Reproduction
 - cross-pollination
 - By coral exoskeletons
 - gene flow
 - Quality of life
 - self-pollination
 - asexual reproduction
 - extinction


 

  cross-pollination       