A claim of what you are going to talk about
-hope it helps my friend
A.an edge on a map because you won't have any boundary's on a ruler, scarf, or a street sign
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).
The correct answer would be B. "Suppose we join hands and fortunes,".