Explanation
The most effective security control to keep a company's physical perimeter protected against intrusions leveraged by social-engineering techniques is employee training. Employee training is a process of educating and raising awareness among staff members about security policies, procedures, and best practices. Employee training can help prevent social-engineering attacks, which are attempts to manipulate or deceive people into revealing sensitive information or granting unauthorized access to resources. Social-engineering techniques can include phishing, impersonation, tailgating, dumpster diving, or baiting. References: CompTIA Network+ N10-008 Certification Study Guide, page 343; The Official CompTIA Network+ Student Guide (Exam N10-008), page 13-8.

A north-south traffic flow is a term used to describe the communication between a user or device outside the network and a server or service inside the network. For example, a public internet user accessing a published web server is a north-south traffic flow. This type of traffic flow typically crosses the network perimeter and requires security measures such as firewalls and VPNs. Reference: CompTIA Network+ N10-008 Certification Study Guide, page 16; The Official CompTIA Network+ Student Guide (Exam N10-008), page 1-9.
North-south traffic flow refers to the flow of traffic between the internal network of an organization and the external world. This type of traffic typically flows from the internet to the organization's internal network, and back again.
Examples of north-south traffic flow include:
A public internet user accessing a published web server
A remote employee connecting to a VPN
An email client sending email to an external server
A customer connecting to an e-commerce website
Reference:
CompTIA Network+ N10-008 Exam Objectives, Version 5.0, August 2022, page 12 CompTIA Network+ Certification Study Guide, Seventh Edition, Todd Lammle, Sybex, 2022, page 17

IaaS stands for Infrastructure as a Service, which is a cloud computing model that provides virtualized computing resources such as servers, storage, and networking over the Internet. IaaS can provide data storage, hardware options, and scalability to a third-party company that cannot afford new devices by allowing them to rent or lease the infrastructure they need from a cloud provider. The company can pay only for what they use and scale up or down as needed. References: https://www.comptia.org/blog/what-is-iaas

The devil is in the details, the question is essentially asking, why would it be possible for an individual to use a card reader, that would be a access control vestibule or mantrap. An individual would typically utilize a card reader if you want to access a particular room via a mantrap.

A hybrid cloud is a cloud deployment model that combines two or more different types of clouds, such as public, private, or community clouds12. A hybrid cloud allows an organization to leverage the benefits of both types of clouds, such as scalability, cost-efficiency, security, and control34.
In the scenario, the company uses a private cloud to host its data center at its corporate office, which ensures greater control over the security of sensitive data. A private cloud is a cloud deployment model that is exclusively used by a single organization and is usually hosted on-premises or by a third-party provider12. A private cloud offers the highest level of security, privacy, and customization, but also requires more resources and maintenance34.
During times when there are increased workloads, some of the company's non-sensitive data is shifted to an external cloud provider, which is most likely a public cloud. A public cloud is a cloud deployment model that is shared by multiple organizations and is hosted and managed by a third-party provider12. A public cloud offers the lowest cost, highest scalability, and widest availability, but also has less security, privacy, and customization34.
Therefore, the best answer is A. Hybrid, which describes a cloud deployment model that combines a private cloud and a public cloud.
Reference:
1: CompTIA Network+ N10-008 Certification Study Guide, page 483
2: CompTIA Network+ Certification Exam Objectives, page 18
3: [What is Hybrid Cloud? - Definition from WhatIs.com]
4: [Hybrid Cloud Computing | CompTIA IT Certifications]