If notable differences are observed when comparing (1) the IR spectrum of samples of an important painting to (2) the IR spectra of chemicals utilized at the time the painting was supposedly made, what should an art conservation scientist conclude? a. the painting was likely crafted by the great Vincent van Gogh b. the painting may not be authentic and further analysis is warranted c. the painting was likely crafted in Ancient Asia d. the painting was likely rock art generated by the Chumash people