It will be a twisted pair so with picture either black / green or orange / white the twists are important so they will never take one cable from one pair and the other from second pair but they could use either pair.
With old phones pos and neg mattered or the phone would not ring with new phones does not really matter phones will work either way around. B (pin2) is negative and A (pin5) is positive. From memory pin 4 is bell and is connected only master socket onwards again not required with modern phones.
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