Which Statement BEST Describes Perceptual Bistability

Which statement BEST describes perceptual bistability?

A) When we look at the Necker cube, signals pass from the retina to the superior colliculus, through the thalamus, and on to the visual cortex that changes our conscious experience.
B) When we look at the Necker cube, activity in some parts of the visual system corresponds to the unchanging retinal image, while activity in other parts of the visual system corresponds to perceptual experience.
C) When we look at the Neckar cube, the retinal image and our conscious experience changes over time.
D) When we look at the Necker cube, it involves involuntary, unavoidable capture of attention by a salient perceptual stimulus that requires a rapid response.