What Is the Most Likely Reason for the Somatosensory Cortex

What is the most likely reason for the somatosensory cortex representing the fingers and hands being so large, but that representing the toes and feet being so small?

A) The skin of the feet and toes are much thicker, and therefore, less sensitive than the skin on the palms of your hands and fingers.
B) The feet have evolved to be less sensitive, and therefore, the area of somatosensory cortex that is served by them, has likewise shrunk since humans started wearing shoes.
C) The amount of cortex representing the two distal limbs are actually equivalent, when you consider the part that represents the feet is hidden within the sagittal fissure.
D) The amount of cortex representing the two distal limbs are actually equivalent, when you consider that the homunculus does not only comprised of cortical surface area, but rather, cortical volume, because the cortex is organized into columns.
E) It is impossible to answer this question with significant certainty.