The ivory-billed woodpecker has been considered extinct for the past

The ivory-billed woodpecker has been considered extinct for the past several decades. Recently, researchers claim to have found a pair of ivory-billeds in Arkansas. Their best evidence is a video that shows a large woodpecker flying away from the camera. The bird has the characteristic large white patches on the trailing edge of the wings. This is one of the factors that distinguishes ivory-billeds from the closely related pileated woodpecker. However, skeptics of the discovery argue that some abnormal pileateds can have extra white on the wing and that the bird in the video is most likely an abnormal pileated. They conclude that the ivory-billed has not been found and is still extinct.

Which of the following, if true, would most strengthen the skeptic’s conclusion that the ivory-billed woodpecker is still extinct?

(A) Before this discovery, the last reported ivory-billeds were seen in Louisiana.

(B) In the same area where the video was shot, researchers also heard the distinctive double-tap used by ivory-billeds.

(C) The first person to discover the ivory-billeds was not a specialist, but professional ornithologists were soon brought in to confirm the identification.

(D) Of the five key fieldmarks that identify ivory-billeds, only the extra white on the wing has been seen and this is also the only feature that occurs on abnormal pileateds.

(E) The bird in the video is clearly seen using the shallow wing beats of the ivory-billed rather than the deeper wing beats of the pileated.