Using powerpoint or impress guarantees that your presentation will do the following a) stay on schedule and end on time b) be clear and understood c) keep your audience engaged and excited d) none of these

The key word in this question is "guarantees". I can speak from experience that using a PowerPoint does not guarantee that the audience will understand everything included or end on schedule. Anyone who has sat through a PowerPoint-driven lecture can tell you that being engaged and excited depends a lot more on content and delivery than the fact that a PowerPoint was used.

While a PowerPoint may help the presentation stay on schedule, be clear and understood, and keep the audience engaged, the mere fact that a PowerPoint was used guarantees none of these. 
Answer is D