Choisissez l'option juste Dans la chambre, on se couche sur l'/la/le.

In French, the phrase "Dans la chambre, on se couche sur" translates to "In the bedroom, one lies down on." In this context, we are looking for the item you would typically lie down on in a bedroom.

Let's consider each option:

• Lit: This is the French word for "bed", which is the object we usually lie down on to sleep or rest. Therefore, it makes sense to choose "lit" in this context.
• Armoire: This is a word for a "wardrobe", a piece of furniture used for storing clothes, not for lying on.
• Rideau: This refers to "curtain", which is something you hang at a window for privacy or to block light, not something to lie down on.
• Miroir: This translates to "mirror", an item used to reflect images and not meant for lying on.

Therefore, the correct option to complete the sentence is "lit", as it is logical for someone to lie down on a bed ("lit") in a bedroom.