What is mandatory for public schools and libraries under the Children's Internet Privacy Act of 2000?

The correct choice reflects the requirement for public schools and libraries under the Children's Internet Privacy Act of 2000, which is to ensure compliance with digital privacy policies. This legislation was enacted to protect the privacy of children under the age of 13 when they access online services. Compliance with established digital privacy policies is crucial as it mandates that these institutions adhere to guidelines designed to safeguard children's personal information.

These policies often include obtaining parental consent for data collection and ensuring that children are aware of their privacy rights online. This focus on privacy and protection is essential in today's digital age where children are increasingly exposed to online environments.

The other options, while they may represent considerations in the realm of internet safety, do not capture the specific requirements laid out by the Children's Internet Privacy Act of 2000 regarding the responsibilities of schools and libraries in relation to children's internet usage.