Respuesta :
D. prepare by studying problems ahead of the meeting and listening carefully.
~APEX
Since Juan is unsure about the problem that is being discussed in the meeting, for him to be able to contribute effectively, it is best for him to (D) prepare by studying problems ahead of the meeting and listening carefully.
This would allow Juan to understand the reason the quality situation and thus reducing his anxiety about the meeting as well since he now at least have the basic information about the topic that would be discussed in the meeting.