I think your answer would be (D.)
I’m not sure, sorry if I’m wrong!!
This answer is true because this is one step to getting there
Due to Union measures such as the Confiscation Acts and Emancipation Proclamation in 1863
If possible I'd say all of them except the fourth one down (parts of ecosystems are independant) but if not I'd say the most valid one is the second one down (healthy ecosystems help animals)