Which of the answer options describes an omphalodium?

The omphalodium is a word for the navel (clinically known as the umbilicus, colloquially known as the ‘bellybutton’), a protruding, flat, or hollowed area on the abdomen where the umbilical cord attached.

The word omphalodium derives from the Ancient Greek word “omphalos”, literally meaning 'navel', while ‘navel’ itself has an Indo-European root. Over the centuries different cultures have taken very diverse views of the navel. An ancient Greek myth tells how Zeus marked the exact centre of the circular flat earth with the Omphalos Stone in Apollo's temple at Delphi. This perception of the central importance of the omphalos/navel is one shared with other cultures and religions - in Arabic-Levantine culture (belly dancing); in India where women often display navels with Saris or Lehengas; in Japan, in Hinduism, in Buddhism where the navel symbolizes the centre where life began and from where energy springs.

On the other hand, the West has been somewhat more reticent in accepting navel-baring, at least until the 20th century. Much of this had to do with religion and morality bound up with competing interpretations of biblical texts, e.g. when Pope Julius II questioned Michelangelo about the navel that appears on Adam in the fresco ceiling painting in the Sistine Capel, “The Creation of Adam”, because Adam was created, not born of a woman. Adam and Eve because they had no parents must have had perfectly smooth abdomens. The picture used is of "The Creation of Adam".