Answer:
B.) rotation of cloud of gas and dust
Explanation:
According to Nebular theory, the sun and the planets were formed from the Solar Nebula. Initially a fragment of the molecular cloud of dust and gases collapsed under its own weight. This contracted portion starts to rotate until a high enough temperature and pressure causes the nuclear fusion reaction in the core to start and form the Sun. The planets were formed from rest of the part of the cloud.
Thus, the second step of Gina's model should be B.) rotation of cloud of gas and dust .
