Am I right? Which sentence is written correctly?

Question

Add a little butter to the pan--you could use olive oil as a substitute, if you like--.

Add a little butter to the pan, you could use olive oil as a substitute, if you like.

Add a little butter to the pan [you could use olive oil as a substitute, if you like].

Add a little butter to the pan (you could use olive oil as a substitute, if you like).<<<<<<This is my answer

Answer 1

Which is your answer? The last one?

Answer 2

Yes, it is the last one.

Answer 3

Yes, that's correct.

Answer 4

Thank you for checking my answer:)

Answer 5

You're welcome.