Answer
Option A - Atoms gain, lose, or share electrons to achieve a full valence shell.
Step-by-step explanation
The octet rule is best explained as atoms gain, lose, or share electrons to achieve a full valence shell complete or to attain electronic configuration of noble gases. The main objective to do this is to attain stability. The octet rule is a rule that shows the view that atoms of elements serve to join like that each atom has eight electrons in its valence shell, providing it the same electron configuration as a noble gas.