First some definitions: ionic bonds always have metals that transfer electrons. Covalent bonds are between nonmetals that share electrons. (Sharing is caring!)
Li is a metal, so right off the bat we know this is not a covalent bond. However, it's not a metal, so we can cross off C as well. The phrase "paired bond" isn't common, so we know the answer must be D. ionic bond.
And in this bond, Li's electrons will transfer to O to make both have a full valence shell. (As opposed to covalent bonds, which share electrons, not transfer completely.)
Break down the table into smaller sections. Memories period by period or if you like by group (like halogens or noble gases). Just say the elements in order everyday 1-10 then when you get those 11-20 and continued.
