It needs to be 2. Otherwise all the people will materialize inside eachother. In fact, everyone will be deposited onto the 2-dimensional pane of the blue portal itself, like an infinitely thing coat of paint, absolutely smearing them.
Think about it. As your fingertips enter the orange portal, they materialize at the entrance of the blue portal. Then your wrist enters the orange portal, where does it materialize at the blue portal?
If your fingers shift to make room, then that has imparted momentum and it’s option B.
If you continue to materialize on the other side of the portal like a mirror image, then for all intents and purposes the blue portal is also moving at the same speed as the orange portal, even if orange ring appears still.
If your fingertips don’t have momentum and your wrist materializes at the portal, then your wrist is occupying the same space as your fingertips. Congratulations, you’re now a paste.
For whatever reason I feel more willing to break conservation of momentum than I am to