Which of the following services is NOT a feature of Google Sites?

Google Sites does not include a built-in blogging platform, which makes this the correct choice. Google Sites is primarily designed as a collaborative website-building tool where users can create and manage web pages easily, but it lacks dedicated blogging features such as post categorization, tagging, comments, and other functionalities typically found in blogging platforms.

On the other hand, the ability to embed YouTube videos is a seamlessly integrated feature, allowing users to enhance their sites with multimedia content. Similarly, Google Sites offers customizable layouts, enabling users to arrange content in a way that suits their needs and preferences. Furthermore, users can restrict access to specific users, providing control over who can view or edit the site. These features contribute to its usability as a collaborative tool for creating informational or project-based websites, but without any built-in blogging capabilities.