Trace impedance for two signal layers between ground planes
I recommend that if your traces are carrying signals fast enough to care about controlled impedance, you simply shouldn't use options B or C.
The problem is that whenever a track on L3 crosses a track on L4, it also crosses a break in the L4 power or ground plane. That means the return current for the L3 signal must find some other way around to get to the other side of the break.
It might not cause a radiation problem because any radiation from the gap is confined by the L5 plane ... or the radiation might find a way to the edge of the board and radiate.
But even if it doesn't radiate, it will cause a discontinuity for the transmission line on L3, and reflections for the signal on the L3 track. If controlled impedance is important for your design, then this is exactly what you're trying to avoid.
So just stick to option A and don't use B or C.