Which evidence did Ottowa scientists collect in researching PCB concentrations in Alaska?

APCBs were found in smaller concentrations in lakes where more salmon spawned.

BPCBs were found in the same concentrations in lakes at similar altitudes.

CPCBs were found in greater concentrations in lakes where more salmon spawned.

DNo PCBs were found in the lakes that were farthest from electronics industry dumping grounds.