Exam CBAP topic 1 question 328 discussion

As part of defining the business analysis approach for a project, the business analyst (BA) identifies the key stakeholders responsible for upcoming activities for the initial phase. The BA emails each of these stakeholders and asks when they can be finished. One stakeholder does not reply, one angrily comments that it is not their job and is too busy, and two respond saying that they do not understand what is being asked of them.
What competencies can the BA draw on that would best assist with getting agreement from all these stakeholders?