On KGS, the 1k label would be placed at the lower boundary of the 1k range (system C).
It does seem like on Pandanet the 1k rank label is in the middle of the 1k half-rank range (centered between the promotion line and the demotion line), so I would characterise that graph more as a system B solution, except applied to half-ranks instead of full ranks.
At least, I assume you are currently labeled as a 1k on Pandanet? Or are you 2k+ there?
Perhaps the Pandanet system could be visualised like this:
This is sort of in between system B and system C.
System B:
System C:
