I would say #2.
I cant see any possible way that it could follow path 1. When it gets to the end of path 1 it is flying in almost a straight line again whilst still banked. If nothing changes on the plane, what has stopped the turn?
What about this scenario:
Plane 1 has banked and followed path 1.
At the end of path one it is still banked but flying straight.
Plane 2 (also flying in a straight line) comes up alongside plane 1 (which is still banked - but flying straight)
Plane 2 then banks so both planes are flying at the same speed, in the same direction and banked at the same angle. But plane 1 will continue straight because it is following the straight line at the end of path 1 but plane 2 will turn sharply to the right because it is at the start of path 1.
I cant see how the plane can return to a straight line if nothing is changed?