The correct option is "Hypervisor." A hypervisor, also known as a virtual machine monitor (VMM), allows multiple virtual machines (VMs) to run on a single physical machine by abstracting and managing the underlying hardware resources. It provides isolation, resource allocation, and control over the VMs, enabling different operating systems to coexist on the same hardware.

When implementing a guest Wi-Fi network for a hotel, ensuring security for both guests and the hotel's internal network involves implementing guest isolation to prevent guests from accessing internal resources. Captive portals with authentication ensure only authorized users gain access. MAC address filtering adds an additional layer of security by allowing only specific devices to connect. Configuring firewall rules restricts unauthorized access and protects sensitive data. These measures collectively enhance security while providing convenient guest access.

Unit testing is focused on verifying the functionality of individual units or modules of code. It is performed early in the development process to detect and fix bugs at a granular level, ensuring that each unit of code functions as intended. This helps in improving code quality, identifying issues early, and facilitating easier integration with other components.

The pop operation removes the last node from a linked list, updating pointers accordingly to disconnect it from the list and deallocate its memory if necessary.

The correct option is "Atomic." In the context of ACID properties, atomicity ensures that database transactions are either fully completed or not executed at all. This means that if a transaction fails or encounters an error, it will be rolled back to its initial state, maintaining data consistency. Atomicity is crucial for reliability and data integrity in database management systems.

Encapsulation is the process of bundling data (attributes) and functions (methods) that operate on the data into a single unit called a class. It helps in hiding the internal state of an object and only exposing the necessary functionality to the outside world. This enhances security, modularity, and reusability in object-oriented programming.

Abstraction in OOP refers to the concept of hiding complex implementation details and showing only essential features of an object. Encapsulation, on the other hand, involves bundling the data (attributes) and methods (functions) that operate on the data into a single unit, i.e., a class. This helps in achieving data hiding and access control.

Option 1 is correct. In a social media platform, it's efficient to have separate tables for users, profiles, and relationships. This allows for easier management and scalability. Foreign keys ensure data integrity and help in querying related information efficiently. Using a single table for users can lead to data redundancy and maintenance issues. A hierarchical structure may become complex and harder to manage as the platform scales. Denormalization, while useful in certain cases, may not be ideal for handling user profiles and relationships in a social media context.

When resolving conflicts in Git, the first step is to identify the conflicting files. git status helps in listing the conflicting files. Once identified, use git diff to view the differences and manually resolve the conflicts in the file. After resolving the conflicts, stage the changes with git add and then commit the resolved changes. Alternatively, you can also use tools like git mergetool to help with resolving conflicts more efficiently.

File system fragmentation occurs when files are broken into pieces scattered across the disk, leading to increased read/write times as the system needs to access multiple fragments. This impacts performance as it introduces delays in retrieving and storing data.