The correct answer is: D. Will, leave
The future tense is used to talk about things that will happen in the future. The simple future tense is formed with the verb “will”. For example, “I will go to the store.”
In this case, we are asking about a specific time in the future, so we need to use the future tense. The simple future tense is the most common way to talk about the future, and it is the best option for this question.
The other options are not as appropriate. Option A, “Shall, leave”, is the formal way to ask about the future. It is not commonly used in everyday speech. Option B, “Will, leaving”, is the progressive form of the future tense. It is used to talk about actions that are happening or will be happening in the future. In this case, we are not talking about an action that is happening or will be happening, so this option is not appropriate. Option C, “Is, going to leave”, is the present continuous form of the future tense. It is used to talk about plans or intentions for the future. In this case, we are not talking about plans or intentions, so this option is not appropriate.
Therefore, the correct answer is: D. Will, leave