Respuesta :
I think the answer is D, because the author says the supporters are overenthusiastic and states another opinion that they'll put American economy in a bad position.
The statement from the passage which shows author bias is the following one:
D) However, overenthusiastic supporters should consider all sides of the issue before taking actions that are already putting America's economy in a precarious position.
It shows bias, since the author sounds like he is criticizing the supporters for acting the way they do. The word choice here also indicates bias: "overenthusiastic", "should". The first is a sure sign that the author does not think their enthusiasm is appropriate; the latter shows the author expressing his opinion or giving a strong recommendation (which is actually pure criticism) as to what those supporters are supposed to do. The author does not sound neutral at all. In fact, he states clearly that he does not agree with the supporters : "...taking actions that are already putting America's economy in a precarious position."