If a technician suspects high disk I/O, the technician should use the Resource Monitor (resmon.exe) to identify the process that is causing the high disk I/O1. Resource Monitor provides detailed information about the system's resource usage, including disk I/O1. The technician can use this information to identify the process that is causing the high disk I/O and take appropriate action1.

Erasing/wiping the hard drives is the best method to dispose of the drives containing PII

First thing you want to do is quarantine/disconnect the affected system from the network so whatever malicious software doesn't spread.

The best choice for accessing the necessary configuration to configure the desktop systems to use a new proxy server is the Internet Options utility. This utility can be found in the Control Panel and allows you to configure the proxy settings for your network connection. As stated in the CompTIA A+ Core 2 exam objectives, technicians should be familiar with the Internet Options utility and how to configure proxy settings.

The user should verify that NFC is enabled on their phone. NFC is a technology that allows two devices to communicate with each other when they are in close proximity2.
NFC (Near Field Communication) technology allows a phone to wirelessly communicate with a payment terminal or other compatible device. In order to use NFC to make a payment or transfer information, the feature must be enabled on the phone. Therefore, the user should verify that NFC is enabled on their phone before attempting to make a payment with it. The other options, such as turning off airplane mode, connecting to Wi-Fi, or enabling Bluetooth, do not pertain to the NFC feature and are unlikely to resolve the issue. This information is covered in the Comptia A+ Core2 documents/guide under the Mobile Devices section.