A Cloud Access Security Broker (CASB) can be used to monitor and control access to cloud-based applications, including unsanctioned SaaS applications. It can help enforce policies that prevent access to high-risk SaaS applications and provide visibility into the use of such applications by employees. Reference: CompTIA Security+ SY0-601 Exam Objectives: 3.3 Given a scenario, implement secure mobile solutions.

Containers are a method of virtualization that allow you to run multiple isolated applications on a single server. Containers are lightweight, portable, and scalable, which means they can save resources, improve performance, and simplify deployment. Containers also enable centralized monitoring and management of the applications running on them, using tools such as Docker or Kubernetes. Containers are different from edge computing, which is a distributed computing paradigm that brings computation and data storage closer to the location where it is needed. Microservices are a software architecture style that breaks down complex applications into smaller, independent services that communicate with each other. Thin clients are devices that rely on a server to perform most of the processing tasks and only provide a user interface.

Three-factor authentication combines three types of authentication methods: something you know (password), something you have (physical token), and something you are (fingerprint scan). Option C satisfies these requirements, as it uses a password (something you know), a physical token (something you have), and a fingerprint scan (something you are) for authentication.
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Note: There could be other options as well that could satisfy the three-factor authentication requirements as per the organization's security policies.

TheHarvester is a reconnaissance tool that is used to gather information about a target organization, such as email addresses, subdomains, and IP addresses. It can also be used to gather information about a target individual, such as email addresses, phone numbers, and social media profiles. TheHarvester is specifically designed for OSINT (Open-Source Intelligence) and it can be used to discover publicly available information about a target organization or individual.

A - a mantrap can trap those personnal with bad intension(preventive), and kind of same as detecting, since you will know if someone is trapped there(detective), and it can deter those personnal from approaching as well(deterrent) B - security guards can sure do the same thing as above, preventing malicious personnal from entering(preventive+deterrent), and notice those personnal as well(detective)