The perceptual grouping of lights in biological motion has been shown physiologically to occur in the area of the cortex.

The correct answer is the "superior temporal sulcus".
Superior Temporal Sulcus is described as the sulcus isolating the advanced temporal gyrus from the middle temporal gyrus in the temporal lobe of the brain. The advanced temporal sulcus is the primary sulcus not so good as the lateral fissure. latest research monitor multisensory processing talents. Studies has shown the recorded activation in the STS because of 5 precise social inputs, and therefore the STS is believed to be implicated in social perception.

Its either a) or b),wind and water erosion gradually widen the canyon