The correct answer is 'To segregate traffic between network devices within the same VLAN'. Private VLANs are used to provide isolation between devices even though they exist within the same VLAN. This is to prevent direct device-to-device communication which can enhance security by limiting potential attack vectors. For instance, if one device gets compromised, it cannot be used to attack other devices within the same VLAN.\n\nThe incorrect options are: 'Connecting multiple switches without the need for routers' refers to trunking or statelessly linking Layer 2 devices, not to the isolation functionality of Private VLANs. 'Encrypting traffic between switches' refers to using security protocols like IPsec, not the segregation role of Private VLANs. 'Allowing multiple devices to share the same IP address' is incorrect because IP addresses are unique identifiers and sharing them is not feasible and would lead to IP address conflicts, unrelated to the use of Private VLANs.