Astronomers have determined that the gas giants are made mostly of hydrogen and helium. Given what you have learned about planetesimal formation through accretion, and the types of materials that condensed at certain distances from the Sun, which of the following is the most likely way that the gas giants formed?
a. Rock, metal, and ices made of materials such as water, ammonia, and methane, condensed into a solid and grew large enough to gravitationally attract hydrogen and helium gas from the Solar Nebula.
b. Hydrogen and helium condensed into a solid and accreted to form the gas giants.
c. Because hydrogen and helium could not condense into a solid at the temperature of the Solar Nebula, the gas giants must have formed elsewhere and been captured by the Sun's gravity.