Learn English – the difference between “Which of the following” and “Which of the below”

There are times where I would tend to favor one over the other, but I'm having trouble figuring out a simple rule that dictates which one I would choose. I would describe:

• The aroma of bread, coffee, and wine, but
• The scent of a skunk, a perfume, a flower, or a woman

Aroma seems to be the more natural word for describing blends of food and spice, while scent seems to be more apt for describing the natural smell of a plant or animal.

Also, not too unlike atoms and molecules, scents seem more fundamental, while aromas seem like more of a mixture or blend. So, I might talk about the scent of a particular candle, but the aromas of the candle store.

Still, the literature has plenty of counterexamples, such as the scent of bread, or the aroma of the flower, or the scent of the wine, so it would be a mistake to interpret any of these thoughts as "rules". The two words are largely synonymous, so there's plenty of room for overlap. If someone said that only one of the two words could be used in a particular context, I'd regard that as smelling fishy.

Which and what have different meanings. Which is used in questions to ask somebody to be exact about one or more people or things from a limited number.

For example, you ask What name do you prefer for your son? because there are many possible names to give to a baby.
Suppose that you're instead talking to somebody who tells you that his wife prefers Michael, her mother prefers Andrew, and his mother likes Alberto. If you ask him Which name do you prefer? you are asking him the name he prefers from among those three; if you ask him What name do you prefer? you are asking him the name he prefers, including any other name that isn't Michael, Andrew, or Alberto.

In your case, Which is correct? could be asked to a person who is talking about two or more options, for example You could do this or that. Your question is essentially asking Between this and that, what is correct?