What is a critical requirement for Interactive Video Ads to ensure optimal user experience?

The correct answer is that interactive elements must not obstruct disclaimers, product information, or primary product visuals. This is a critical requirement because it ensures a positive user experience and maintains the clarity and effectiveness of the ad. Obscuring essential information can lead to user frustration, misinterpretation of product details, or missed calls to action, ultimately diminishing the ad's performance. The other options are incorrect because they impose unnecessary restrictions or make assumptions about optimal placement. Interactive elements can appear throughout the video, not just at the end, as long as they don't obstruct critical content. While central placement can be good for viewability, it's not a universal rule and depends on the ad's design and content. The primary concern is always to preserve the integrity of the ad's core message and information.