According to the theory of unconscious inference, what calculation leads to size constancy?

A) multiplication of the size of the retinal image by the distance of the object from the viewer
B) multiplication of the proximal stimulus by the retinal stimulus
C) addition of the size of the retinal image and the size of the proximal stimulus times the distance of the object from the viewer
D) the distance of the distal stimulus, minus the size of the retinal image

According to the theory of unconscious inference, size constancy is achieved by multiplying the size of the retinal image by the estimated distance of the object from the viewer. This calculation takes into account the size of the object on the retina and the distance of the object to determine its true size, which is perceived as constant despite changes in viewing distance. Option B is incorrect because it refers to a multiplication of two stimuli, rather than the retinal image and the distance of the object. Option C is incorrect because it involves an unnecessary addition of the proximal stimulus size, which is not used in the calculation for size constancy. Option D is also incorrect because it refers to the distance of the distal stimulus, rather than the distance of the object, which is the essential factor in size constancy.