Answer:
D) an effective manager
Performing a large number of projects is making a dream come true. Objective-realization is an indicator of a manager's success. "An efficient manager" is misleading because it says nothing about how good Brenda is when performing tasks. Likewise, "a good spokesperson" and "a good resource allocator" are not right, as there is no evidence of Brenda's ability as a knowledge provider (speaker) or decision-maker (resource allocator) in the article.