I believe it should be 1. Hope this helps.
Answer:
the answer would be the first one which is sexual reproduction
Variation- Heritable differences that exist in every population are the basis for natural selection
Overproduction- Competition for resources for resources
adaptation- A trait that helps an organism survive and reproduce
decent with modification- Natural Selection will result in species with adaptation that are well suited for survival and reproduction.
True- it's not good if the scientist changes the outcome and reads data with a bias because then it's not 100% honest.