Question

Can some one please help me

Answer 1

The phrase from this passage which demonstrates that the author is identifying a source of debate is C. "the controversy stems from..."
To stem from something means to originate from, so this would be the logical answer. 

Answer 2

The third alternative is correct (C).

A debate is composed of at least two different types of opinions. When the author uses the expression "The controversy stems from," he is introducing a subject that does not have general agreement, that is, it is a subject that divides opinions and generates debate. In this case the controversy concerns the interpretation of the Second Edition of the American Constitution on the possession of the firearm. Some find that Second Level restricts the possession of weapons while others feel it does not restrict.