I want to know the answer to the following question:
In what sort of electrolyte does the oxide layer on an aluminum anode remain stable?
All the background I'm provided with is that "Charles Pollak (born Karol Pollak), the inventor of the first electrolytic capacitors, found out that the oxide layer on an aluminum anode remained stable in a neutral or alkaline electrolyte, even when the power was switched off.". Is that enough to answer the question?