Funny fact that will send you bananas.
A banana is a berry yet raspberries are not.
Temperature storage is a main factor with bananas, too cold they go black, too hot and they turn to mush.
When I was young and my mum was skint on a school day trip out she would make me a banana butty, by the time I got to eat for lunch it was black slop in a sandwich.
Am not a banana man myself but I would go with 6.
Quick edit and quote.
"The definition includes many
fruits that are not commonly known as
berries, such as grapes, tomatoes, cucumbers, eggplants, bananas, and chili peppers.
Fruits excluded by the botanical definition include strawberries, raspberries, and blackberries, which are aggregate
fruits; and mulberries, which are multiple
fruits."