Which statement describes Linus Pauling's contribution to the understanding of DNA structure?

Having first discovered the spiral shape of proteins, Linus Pauling used x-ray technology to hypothesize that the DNA molecule consisted of two consistently spaced strands that formed a spiral shape.

Linus Pauling studied DNA base pairing.

Having originally studied proteins, Pauling proposed that DNA was a three-chained helix with a sugar-phosphate backbone at the center and bases sticking out from the backbone.

Linus Pauling conducted experiments to prove that DNA carried genetic information.