Why is access control necessary for files in the operating system?

Access control is fundamentally important for protecting files within an operating system because it serves as a mechanism to enforce security policies regarding who can view or modify these files. By implementing access controls, the system can limit permissions to ensure that only authorized users have the capability to access or alter specific files.

The necessity of access control is particularly highlighted by the risk posed by malicious users attempting to access or disrupt the personal files of others. Without proper controls in place, a user could inadvertently or deliberately modify sensitive information, leading to data breaches, loss of integrity, or unauthorized disclosure of private data. Therefore, maintaining robust access control mechanisms is essential to safeguard users' personal files and uphold the overall security of the operating system.

The other options do not accurately address the core purpose of access control in this context. Access controls are not primarily designed to prevent the creator from deleting their own files, nor do they aim to restrict authorized users from reaching files they should have the right to access. Additionally, access control is not directly related to protecting main memory, as its focus lies in securing file systems and user data from unauthorized operations.