Answer:
Sentence 6
Step-by-step explanation:
The passage discusses why it is necessary to remove mountain goats from Olympic National Park and transport them to North Cascades National Park. The sentence transitions from the opening description of the transportation process (“This removal process may be complicated”) to the assertion of its importance (“but it is necessary”) that will be discussed throughout the rest of the passage. The second paragraph explains how the goats damage the environment of Olympic National Park, the third paragraph explains how they endanger the safety of human visitors, and the fourth paragraph explains why North Cascades National Park is a better location for the goats.