Q: Fact 1: Cutting down trees has a negative impact on an ecosystem. Fact 2: All oaks are trees. Given the two facts above, what has a negative impact on an ecosystem?

pick from the following.
i. planting trees
ii. cutting down oaks
iii. Destroy bridges
iv. planting oaks
v. adding habitat
vi. deforestation
vii. massive damage
viii. Pesticides
The answer is:
ii.