The one that no longer exists where banana flavoured candy derives its flavor from.
That's actually a myth. See Wikipedia.
The Gros Michel has a higher concentration of isoamyl acetate, the ester commonly used for "banana" food flavoring, than the Cavendish.[12] This higher concentration is responsible for the myth that banana flavoring was based on the Gros Michel, but artificial banana flavor was not based on any specific cultivar.

Came here to mention that. From the article you linked: