WitP - Chinese in Russia?

[Gilgawath]

Can anyone provide a ruling on the following scenario?

4 Chinese units, defeated in combat, are forced to retreat into Russian territory. I assume that if I pursue them I will activate the Russians, as its only 04/42 not something I want to do.
Should these units:
a) now be classed as Russian controlled and only allowed to re-enter the game upon Russian activation? :)
b) be allowed to continue normally? :angry:
c) be allowed to function normally but without replacements available until they reach a Chinese occupied base (long way off since all on Northern China is now under Japanese control):chin:
d) something else (please elaborate):stir:

Thanks

Tony Ellis