Question

Which of the following sentences is written correctly?

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).

Answer 1

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

Explanation: Commas and periods are the only necessary punctuation.