A volleyball coach analyses video footage of previous matches to determine where to best direct the serve in various situations during a match - HSC - SSCE Personal Development and Physical Education - Question 11 - 2019 - Paper 1

To identify the performance elements that the coach is trying to improve, we must analyze the scenario given. The coach is focused on improving the athletes' ability to direct serves effectively. This indicates a focus on both the decision-making processes of the athletes and their execution of tactics during the game.

Therefore, the correct answer is D: Decision making and tactical development, as this encompasses the necessary skills to make quick decisions about where to serve the ball in specific match contexts and the tactical understanding required to execute those decisions effectively.