Answer:
"Will you send" is the correct answer.
Step-by-step explanation:
The complete sentence with the correct choice will be - When will you send us the final draft of the report?
The presence of the word "when" and the question mark makes the statement to be interrogative.
Use of the word "will" states the tense to be future tense.
The given question is in future simple tense which is formed as - Question word + will + pronoun + base form of a verb.