Answer: The right answer is the A) Acknowledged.
Explanation: Just to elaborate a little on the answer, it can be added that reading his report truly impressed her, to the extent that she arranged a meeting to discuss his promotion. They are asking you to replace the word with a more precise term. For that reason, option D should be discarded, since "noticed" still sounds vague. Likewise, options B and C can be also discarded, since she did not only grasp the worth of the report, but communicated it publicly by arranging a meeting and discuss his employee's promotion. To acknowledge implies to disclose someone's agreement with something—in this case a boss' favorable opinion of her employee's remarkable endeavor.