This is a tough choice, but I'm going to go with option 1, and I think I have a solid reason for doing so. Options 2 and 3 offer good payouts, but we can get those payouts later in the story, most likely. If we save Lukas from what are likely Nod agents following him, we could rally the anti-Nod segment of the population. That's basically what we came here to do, and if we don't do this, we risk potentially losing it entirely. We can unlock a slew of options for progression here that could become unavailable if we try to rush the main objective, basically.