Which of the Following Explains the Rocky Nature of the Inner

Which of the following explains the rocky nature of the inner planets?

A) The lighter elements (hydrogen and helium) were sucked in by the Sun's gravity.
B) The Sun's gravity attracted the rocks to the inner part of the Solar System.
C) Only the rocky material could condense at the higher temperatures of the inner part of the Solar nebula.
D) As the Solar nebula was spinning, the light gases were tossed to the outer parts of the disk.