Port security is a feature that can be configured on a switch interface to limit and identify the MAC addresses of workstations that are allowed to connect to that specific port. This can help ensure that only a specific workstation (or workstations) can connect to the interface. According to the CompTIA Network+ Study Manual, "Port security can be used to specify which MAC addresses are allowed to connect to a particular switch port. If a port security violation is detected, the switch can take a number of different actions, such as shutting down the port, sending an SNMP trap, or sending an email alert."

A divide-and-conquer approach is a troubleshooting method that involves breaking a complex problem into smaller and more manageable parts, and then testing each part to isolate the cause of the problem.
In this scenario, the technician is using a divide-and-conquer approach by pinging the default gateway and DNS server of the workstation, which are two possible sources of connectivity issues.
By pinging these devices, the technician can determine if the problem is related to the local network or the external network.

Explanation
The attack which, if successful, would provide a malicious user who is connected to an isolated guest network access to the corporate network is VLAN hopping. VLAN hopping is an attack technique which involves tricking a switch into sending traffic from one VLAN to another. This is done by sending specially crafted packets, which force the switch to send traffic from one VLAN to another, thus allowing the malicious user to gain access to the corporate network.
VLAN hopping is an attack technique which involves tricking a switch into sending traffic from one VLAN to another. This is done by sending specially crafted packets, which force the switch to send traffic from one VLAN to another, thus allowing the malicious user to gain access to the corporate network. According to the CompTIA Network+ N10-008 Exam Guide VLAN hopping is a type of attack that is used to gain access to network resources that are not meant to be accessible by a user on a guest network.

The question asks about the best security feature to provide secure connections and keep the medical data protected for patients who use Wi-Fi in the waiting room of a medical building.
The answer is isolating the guest network, which means creating a separate network for the guests that has no access to the internal network where the medical data is stored. This way, the guests can use the internet without compromising the confidentiality, integrity, and availability of the electronic protected health information (ePHI).
Securing SNMP, MAC filtering, and disabling unneeded switchports are also security features, but they are not the best solution for this scenario. Securing SNMP means encrypting the Simple Network Management Protocol, which is used to monitor and manage network devices. MAC filtering means allowing or denying access to the network based on the MAC address of the device. Disabling unneeded switchports means turning off the ports that are not in use to prevent unauthorized access. These features can help prevent unauthorized access to the network, but they do not isolate the guest network from the internal network, which is the main requirement for this question. Reference:
Medical Grade WiFi: Essential Features for Every Hospital or Clinic
HIPAA WiFi Compliance: Your Complete Guide to the Latest Privacy Rule Requirements Wireless Medical Devices CompTIA Network+ N10-008 Study Guide