The second choice is a fragment, not a complete sentence.
I believe the correct choice is number one, because if you turn the sentence around, it answers the question of why the crowd is gathered. You may want to confirm on the website chompchomp.com (Grammar Bites).
Answer:
B. By moving to Appleton, Wisconsin
Explanation:
Please give us a question
Answer:
the answer is d because a period of war has just. ended.
Answer:
Its D. Messenger system.
Explanation:
Just took the test and its correct!