Final answer:
The sentence 'She will have finished her homework by the time I arrive.' is in the future perfect tense, which describes actions that will be completed by a specific future time.
Step-by-step explanation:
The correct tense of the verb in the sentence "She will have finished her homework by the time I arrive." is future perfect tense. This tense is used to describe an action that will have been completed by a certain future point in time. The future perfect tense involves the auxiliary verb 'will' to indicate the future aspect and 'have' to indicate the completion of the action, followed by the past participle of the main verb, 'finished' in this case.