What previously unanticipated planet-wide feature of Titan might explain the surprising Cassini finding that its surface is not in exactly synchronous rotation with its orbit around Saturn?

A) A hemisphere-sized ocean of liquid methane and ethane.

B) A globe-spanning subterranean network of methane-filled caverns.

C) A globe-spanning chain of active cryovolcanoes.

D) A globe-spanning desert of hydrocarbon-rich “sands”.

E) A globe-spanning subsurface ocean of water and ammonia.