As a Result of Measurements by the Galileo Spacecraft,what Is

As a result of measurements by the Galileo spacecraft,what is now believed to be the internal structure of Io?

A) iron core overlaid by a molten mantle and rocky crust
B) core of rock overlaid by a thick mantle of water ice
C) entirely or almost entirely rock, with no evidence of ice or a differentiated metallic core
D) iron core overlaid by a rocky mantle and a deep ocean of liquid water