How does the following sentence develop the main claim of this passage?

"face photographs in which the features had been scrambled were not matched with green at all."
a) this sentence provides personal testimony from an experiment participant who worked with the scientists.
b) this sentence provides a counter-claim to the thesis put forward by the scientists doing the experiment.
c) this sentence identifies one of the weaknesses present in the methodology used to conduct this experiment.
d) the sentence provides more evidence that somehow human perceive the color normal faces differently than other objects.