Curator: The decision to restore the cloak of the central figure in Veronese' s painting from its present red to the green found underneath is fully justified. Reliable x-ray and chemical tests show that the red pigment was applied after the painting had been completed, and that the red paint was not mixed in Veronese' s workshop. Hence it appears likely that an artist other than Veronese tampered with Veronese' s painting after its completion. Art critic: But in a copy of Veronese' s painting made shortly after Veronese died, the cloak is red. It is highly unlikely that a copyist would have made so major a change so soon after Veronese' s death. The assertion that a later artist tampered with Veronese's painting serves which one of the following functions in the curator's argument?
A: It is a clarification of a key term of the argument.
B: It is a particular instance of the general position to be defended.
C: It is a subsidiary conclusion that supports the argument's main conclusion.
D: It is a reiteration of the main point that is made for the sake of emphasis.
Choose A, B, C or D as your solution.
C