Answer:
Censorship.
Step-by-step explanation:
The act of removing anything from a particular place as an act of restricting or banning it from being accessible by the people is known as censorship. This act involves the removal of anything, be it books or images or anything that is deemed dangerous or inappropriate to be put in the public display or public access.
This act of limiting the student's access to a certain type of 'knowledge' is done in many schools and colleges across the world and even in the United States. This is to make sure that the children are not exposed to any information that is detrimental to society and the people as a whole. Such acts of removing controversial topics from public high school libraries are a form of censorship or banning.