Final Answer:
Dave is following the design principle of Simplicity when he removes excessive effects and transitions from his presentation files. Option A is the answer.
Step-by-step explanation:
Dave's decision to eliminate distracting effects and transitions aligns with the design principle of Simplicity. Simplicity in design emphasizes the removal of unnecessary elements, fostering clarity and a more focused audience engagement.
By streamlining the presentations, Dave ensures that the audience's attention is directed towards the content rather than being diverted by flashy or superfluous visual effects. This approach not only enhances the overall aesthetic appeal but also improves the effectiveness of communication, as the audience can better absorb and understand the key messages without unnecessary distractions.
Option A is the answer.