Answer :
I have been working all afternoon and have just finished the assignment. That is option A.
What is present perfect continuous?
Present perfect continuous is used to denote an unspecific time between after and before now.
The word "I" is usually used with plural "have" instead of "had".
Therefore, I have been working all afternoon and have just finished the assignment.
Learn more about present perfect continuous here:
https://brainly.com/question/25105940
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