It is the position that Prakash's argument needs to refute in order to establish its conclusion. It is the conclusion of Prakash's argument. It is used to clarify what Prakash means by "factual matter, " by contrasting it with a matter of opinion. It is offered as a way of conceding to Murali that the painting may not be authentic.
Murali: You are wrong to assert that the question of the painting' s authenticity is a factual matter. You may believe that the painting is authentic, but this is an opinion and not a fact. Experts disagree about whether or not the painting is authentic. Prakash: Whether a painting is beautiful or not is merely a matter of opinion, but the question of who painted it is not. A painting is either authentic or not. Thus the authenticity of the painting is a factual matter.
Which one of the following most accurately describes the role played in Prakash's argument by the claim that whether a painting is beautiful or not is merely a matter of opinion?