The correct answer is: D. Will, go
The future tense is used to talk about things that will happen in the future. In this case, the question is asking about when the person will go to Delhi. The most common way to express the future tense in English is to use the verb “will”. For example, you could say “I will go to Delhi tomorrow” or “We will go to Delhi next week”.
The other options are not as appropriate in this context. Option A, “shall”, is a formal way of asking for permission. Option B, “going”, is the present participle of the verb “to go”. Option C, “is, going to go”, is the future tense of the verb “to go”. However, it is not as common to use this form when asking about a specific time.
In conclusion, the correct answer is “Will, go”. This is because it is the most common way to express the future tense in English.