Underrealm Lich and Divination
It's option A). From the Comprehensive Rules:


  120.2. Cards may only be drawn one at a time. If a player is instructed to draw multiple cards, that player performs that many individual card draws.


Each individual card draw gets replaced by "instead look at the top three cards of your library, then put one into your hand and the rest into your graveyard."

In fact, this very situation is mentioned in the Rulings below the card on Gatherer:


  If an effect instructs you to draw multiple cards, each draw is performed—and replaced by Underrealm Lich’s ability—one at a time. This means that if you’re drawing two cards, you’ll look at the top three cards of your library, put one into your hand, put the other two into your graveyard, and then repeat the process with the next three cards in your library.