An educator should use a variety of educational aids to help ensure:

Using a variety of educational aids is particularly effective in increasing retention of the material because it caters to different learning styles and preferences among students. Some students may grasp concepts better through visual aids, such as charts or videos, while others may benefit from hands-on demonstrations or auditory materials like lectures. By incorporating these diverse teaching tools, the instructor can reinforce key concepts, making it easier for students to remember and apply what they've learned. This multi-faceted approach engages students more fully, promoting better understanding and effectiveness in learning.

Other options, while they may seem related, do not encapsulate the primary purpose of varied educational aids as well as retention does. For instance, streamlined lessons and uniform teaching methods may support organization and consistency, but they don't enhance individual understanding and memory retention in the same impactful way. Similarly, while varied aids can contribute to consistent test scores, that is more of an indirect benefit rather than the main objective. The core benefit remains the improvement of students' ability to retain and recall information confidently.