Afags are correct because the question is strictly about what would happen IN THE GAME, not real life. Portals in the game function as doors, simple as that.
>BUT MUH MOON PROVES B!
The moon scene doesn't prove shit and doesn't even remotely model real life. Neither the Earth nor the moon are even fucking moving in the game. The game is a vague approximation of an extremely simplified physical model because all of the complexities of real world physics would make the game much harder to not only program but to play.
We're talking about fake portals in the game called Portals, not real life wormholes. Portals in the game called Portal do not follow the same real world physics of theoretical wormholes. Real world physics might be how we get the answer of B but that's not what the Portal Problem is about. It is about the titular portals in the fucking game as the game models them. Bfags want to feel so much smarter than somebody else but they constantly miss that detail and try to apply mathematics that don't fucking exist in the game we're fucking talking about.