C. Arachnida.
hope it's correct.
Conservation is the protection of an organism or a group of organisms (like an endangered species or forests).
Biodiversity is the numerous amounts of species habitated in our earth. The more biodiversity, the better.
Conservation protects biodiveristy, thus, allowing more species to survive and thrive.
Explanation:
The experimenter alters the independent variable with the hopes of collecting data about how the dependent variable changes in response.Other variables have to be controlled so that any changes of the dependent variable are attributed to the known independent variable.