Final answer:
Julia should write an average of five points on each slide of her video presentation. Therefore, the correct option is A.
Step-by-step explanation:
When creating a video presentation, it is important to keep the number of points on each slide manageable for viewers to absorb. For Julia's presentation, she needs to mention 15 points within 2 to 3 slides. To divide the points evenly, Julia should write an average of five points on each slide. This will allow her to provide enough information without overwhelming the audience with too much content on a single slide.