You are presented with the question "What has to happen for roundworms to reproduce?" and the following answer choices: 
- Fertilization
 - rapid expansion
 - Plants growth
 - an organism's body
 - permineralization
 - bioaerosols
 - temperature changes
 - competition

Now knowing that roundworms reproduce sexually and fertilisation is a key feature of sexual reproduction, choose the best answer.


 

 Fertilization        