B. Three are lost creating Al+3. Because atoms have and equal amount of Protons and Electons when neutral losing 3 electrons will create a positive Al ion Al+3
This is called an aluminum cation. Aluminum forms bonds with anions in which it can donate its three valence electrons so it can achieve stable electron configuration. Stable electron configuration is having 8 electron in the outer shell. By donating its 3 outer valence electrons, the aluminium will have the more stable 2.8 electron configuration. The +3 means it has lost 3 electrons hence has 3 extra protons (that are not matched by an electron) in its nucleus (also indicating its valency).
