An access control system primarily allows which type of individuals to enter secured areas?

The correct answer reflects the primary function of an access control system, which is designed to manage entry into secure areas by allowing access to individuals who have been vetted or authorized in some way. This typically means those who are presumed friendly or known to the organization, such as employees, authorized visitors, or individuals with the proper credentials.

An access control system aims to create a secure environment by limiting entry to authorized personnel, thereby reducing the risk of unauthorized access or potential security breaches. This is accomplished through various means such as keycards, biometric scanners, or password systems that question the identity of entrants and ensure that only those who meet specific criteria, i.e., presumed friendly people, are granted access.

Other choices, while they may reference different scenarios or individuals, do not align with the fundamental purpose of access control systems as effectively as the selected answer. Unknown individuals, for instance, would not typically gain entry since they lack authorization, while 'all individuals' implies an unrestricted access scenario that contradicts the very nature of security systems. 'Contracted employees only' narrows the scope too much and does not encompass all authorized personnel that an access control system would ideally permit.