Gyri and Sulci

First clue, the color-altered image at left is not of gyri and sulci. What is it?

Click on the letter that you think indicates the correct choice:
a. an aerial view of Zabriskie Point in California's Death Valley.

b. a close-up of the skin of an elephant.

c. an aerial view of Twenty Mule Team Canyon in Death Valley.

d. a satellite image of a field of sand dunes.

e. none of the above.

Quo Vadis?
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