Which of the following is NOT a customization option available in Community Builder?

In the context of Community Builder, the platform offers a variety of customization options to enhance the visual aspects and branding of a community. Options such as changing font styles and weights, modifying header and background colors, and uploading a company logo are all features that allow administrators to personalize the community to align with organizational branding and user experience.

Customizing user login processes, however, typically refers to more intricate configurations that go beyond the aesthetic changes supported directly within Community Builder. This might involve modifications to authentication methods, implementation of single sign-on (SSO), or adjustments to the overall security protocols governing user logins. These types of customizations require deeper integrations and configurations that are generally handled outside of the Community Builder's user interface.

Therefore, while Community Builder excels in visual and branding customizations, changing the user login processes is not one of the built-in options, making this the correct answer to the question.