Astar begins its formation as gravitational forces cause instability within a

A star begins its formation as gravitational forces cause instability within a molecular cloud. This is caused by compression in the clouds, due to radiations emitted by the bigger stars. The molecular clouds are dense regions of gas and dust. The temperature inside is very cold, which allows atoms to fuse together and leads to the formation of the stars. 

B) raising the temperature and reducing the volume of the gas.|-/ 

Is there any opitions? if you have the periodic table, the noble gases are 8a family, the halogen are the 7a family, and the nonmetal are  carbon, nitrogen, phosphorus, oxygen, sulfur, selenium, fluorine, chlorine, bromine, iodine and astatine.