Unknown Fruit Seedling ?

Farouk starts with ...
Hello All,

I have an unknown possible fruit seed plant emerge, it is the only thing that sprouted from the pot so it must be something I stuck in there & forgot about.

It could be 4 things:
1 - Purple Mangosteen - doubt it now was thinking it was in warmer season but it survived the winter here so it's def not.
2 - Red Custard Apple (bullocks heart - Jamaican?)
3 - Black Sapote - I think its a high chance it will be the sapote looks similar too.
4 - Your guess or experienced knowledge ?

Thank you

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