Identify the sentence with correct use of the future perfect tense:
A. By next year, they will have completed their project.
B. By next year, they will complete their project.
C. By next year, they will be completing their project.
D. By next year, they will had completed their project.
The correct form is "By next year, they will have completed their project," using the future perfect tense for an action that will be completed before a specific future time.