Perhaps you typed the options with words in italics, but they do not show for some reason. Therefore, I cannot tell which letter it is, but I can still give you the proper answer for this question.
Answer:
The phrase that should be italicized is <em>a la carte.</em> Thus, the correct letter will be the one that shows:
When you order food at a restaurant, do you prefer to order <em>a la carte</em>?
Explanation:
The phrase <em>a la carte</em> is foreign. It is a French expression used when you can order items on a menu separately instead of as a set meal. When we use words or expressions such as this one in writing, we should italicize them. Italics will distinguish them, showing they are written in their original language.