Final answer:
The correct phrase that completes the conversation is 'il fera chaud'.
Step-by-step explanation:
The correct phrase that completes the conversation is: il fera chaud.
In the dialogue, Léa asks Marie if she has seen the weather forecast for tomorrow. In response, Marie says 'Oui, demain', which means 'Yes, tomorrow'. To complete the conversation, the phrase 'il fera chaud' is appropriate, as it means 'it will be hot'.
Therefore, the correct answer is D. il fera chaud.
Learn more about Completing a conversation in French about the weather