Which One of These Statements About All Four of the Giant

Multiple Choice

Which one of these statements about all four of the giant planets is true?

A) The giant planets are almost entirely made up of hydrogen and helium; only about 1 percent of the planets' mass is made up of heavier elements.
B) The giant planets are thought to have substantial rocky cores.
C) Liquid metallic hydrogen makes up a large part of the interiors of the giant planets.
D) The spin axes of the giant planets are all approximately perpendicular to their orbital planes.