question:  Which of these was not a consequence of the Great Atomic Wars?
context: The planet itself was tough enough—barren, desolate, forbidding; enough to stop the most adventurous and dedicated. Nothing but what had stopped us could stop a sandcat: sand in the delicate mechanism of the atomic engine. But no; she blamed it all on me somehow: So we were out walking on the spongy sand of the Martian desert. "Maybe there isn't any uranium in this sector at all. Behind us somewhere was the comfort of the Dome, ahead nothing but the mazes and gullies of this dead world. "Heroes, hell!" "Heroes," she said bitterly. She had been just as much inflamed by the idea of coming to Mars to help in the search for uranium as I was. We knew the pay was poor, but we had felt it a sort of obligation, something we could do as individuals to keep the industries of radioactives-starved Earth going. No, we had decided together to come to Mars—the way we decided together on everything. Maybe we shouldn't have come to Mars after all. I watched her, sleeping peacefully, a wayward lock of her soft blonde hair trailing down over one eyebrow, and it seemed hard to believe that we'd exchanged Earth and all it held for us for the raw, untamed struggle that was Mars. It's because we wanted to keep what we had. We just liked our comforts, and wanted to keep them. We had no ties on Earth that couldn't be broken without much difficulty. Heroes. It had been spun on us only a short time ago, I realized. The oxygen cannisters weren't attached to his back as expected, though. I thought I knew everyone on sparsely-settled Mars. Earth needed radioactives, and the only way to get them was to get out and look. The great atomic wars of the late 20th Century had used up much of the supply, but the amount used to blow up half the great cities of the world hardly compared with the amount we needed to put them back together again.
output:  Multiple planets were settled by various countries in a display of power
options:  Limited resources ran out over time  Multiple planets were settled by various countries in a display of power  All major types of power sources changed  Earth decided to run supply missions to Mars