Re: It is generally believed that an Indian tribe known as “The

In the argument above, the two portions in boldface play which of the following roles?

The first is a commonly held belief that the argument seeks to refute; the second is evidence used in that refutation.
The second is not evidence: it's a conclusion: "therefore ...."

The first is a generalization that the argument accepts as true; the second is the main conclusion of the argument.
The first is not accepted by the argument, it refuses it.

The first is evidence used to support a conclusion that the argument opposes; the second is the main conclusion of the argument.
The first is simply not evidence.

The first is a conclusion that is generally accepted as true; the second is a conclusion that refutes it.
IMO CORRECT

The first is an intermediate conclusion that is generally accepted as true; the second is the main conclusion of the argument.
The first is not "an intermediate conclusion", it' s a conclusion period. E says that there are two conclusions of the argument, but this is not true as the argument has only one conclusion, so the is no such thing as an intermediate and main conclusion.