Explanation
The best option to implement a secure connection between two different locations is IPSec (Internet Protocol Security). IPSec is a protocol suite that provides security for IP-based communications over networks. IPSec can encrypt and authenticate the data packets between two endpoints, such as routers, firewalls, or VPN gateways. IPSec can also provide integrity, confidentiality, and replay protection for the data.
Reference: CompTIA Cloud+ Certification Exam Objectives, Domain 2.0 Security, Objective 2.2 Given a scenario, implement appropriate network security controls for a cloud environment.

Explanation
Allocated guest resources is what the administrator should check next after receiving an email from the virtualized environment's alarms indicating the memory was reaching full utilization and noticing that one out of a five-host cluster has a utilization of 500GB out of 512GB of RAM. Allocated guest resources are the amount of resources or capacity that are assigned or reserved for each guest system or device within a host system or device. Allocated guest resources can affect performance and utilization of host system or device by determining how much resources or capacity are available or used by each guest system or device. Allocated guest resources should be checked next by comparing them with the actual usage or demand of each guest system or device, as well as identifying any overallocation or underallocation of resources that may cause inefficiency or wastage.

Explanation
These are the components of the hypervisors that should be upgraded by the administrator who is performing upgrades to all the hypervisors in the environment. A hypervisor is a software or hardware that allows multiple VMs (Virtual Machines) to run on a single physical host or server. A hypervisor consists of various components, such as:
The firmware: This is the software that controls the basic functions and operations of the hardware or device. The firmware can affect the performance, compatibility, and security of the hypervisor and the VMs. The firmware should be upgraded to ensure that it supports the latest features and functions of the hardware or device, as well as fix any bugs or vulnerabilities.
The operating system: This is the software that manages the resources and activities of the hypervisor and the VMs. The operating system can affect the functionality, reliability, and efficiency of the hypervisor and the VMs. The operating system should be upgraded to ensure that it supports the latest applications and services of the hypervisor and the VMs, as well as improve stability and performance.

Explanation
https://www.cloudflare.com/learning/cdn/what-is-a-cdn/
"A content delivery network (CDN) refers to a geographically distributed group of servers which work together to provide fast delivery of Internet content."