Which of the following social media platforms is NOT mentioned as being used by the EU?

The correct choice indicates that TikTok is not mentioned as a platform being used by the EU. The reasoning behind this is rooted in the context of how the EU typically engages with social media for formal communication and public outreach. Historically, platforms like Facebook and Twitter have been extensively utilized by governmental organizations and institutions for announcements, discussions, and sharing information with citizens. These platforms allow for a wide audience reach and have established frameworks for official communication.

Google+ was also a notable presence in the social media landscape, albeit it has since been discontinued. However, its prior usage demonstrates that the EU had recognized and engaged with various social media platforms.

On the other hand, TikTok, while it has gained immense popularity, particularly among younger demographics, has not been a primary channel for the EU's communication strategy. The EU tends to focus on platforms that align with its goals for transparency, information dissemination, and formal engagement with citizens, which might explain the absence of TikTok from their list of utilized social media platforms. Thus, identifying it as not used by the EU highlights a nuanced understanding of the platform preferences in official communication contexts.