I'd say 6 because the main idea is how volcanoes are destructive but they can also help us and sentence 6 says that exact thing
Stab herself with a knife(Kill herself)
Semicolon is used when separating 2 closely related independent clauses.
Colon is used when listing things, writing biblical references, between hours and minutes, proportion between 2 numbers, or between 2 clauses related to the first
So we'll write this one as-
Flour Power: A Guide to the Modern Green Kitchen
You're answer's the last choice
