Being proactive means taking initiative, not waiting for others to act first, and being responsible for what you do. The opposite of proactive is reactive. Reactive people tend to react to what goes on around them.
Proactive people act based on principles and purpose.
Think things through. Plan your work. Planning requires that you set realistic goals, not only for your courses, but also for the various assignments you have to complete. Take a few minutes to write out your goals and then list the steps to achieve them. The answer is quadrant 4 because these activities usually do not cause any stress.