As Briana Drove Down the Highway,the Pickets of the Fences

As Briana drove down the highway,the pickets of the fences moved past her in a blur,but the mountains in the distance didn't appear to move at all.What was Briana experiencing

A)  binocular cue for depth called retinal disparity 
B)  monocular cue for depth called motion parallax 
C)  binocular cue for depth called convergence 
D)  pictorial cue for depth called texture gradient