The correct option is Waterfall. The Waterfall model follows a sequential approach, progressing through phases like Requirements, Design, etc.

Designing a thread management system for a web server application involves strategies for high performance and scalability. Using a thread pool allows for the reuse of threads, reducing the overhead of thread creation and destruction for each request and improving overall performance. Implementing asynchronous I/O operations helps in avoiding thread blocking, enabling the server to handle more concurrent requests efficiently. Load balancing across multiple servers distributes incoming requests evenly, enhancing scalability by utilizing resources effectively. Mutex locks are essential for ensuring thread-safe access to shared resources but may not directly contribute to performance and scalability in the context of handling concurrent requests in a web server application.

Server-side rendering (SSR) involves generating HTML content on the server before sending it to the client. This approach reduces client-side processing requirements, leading to faster initial page load speeds and improved SEO performance. Frameworks like Next.js for Node.js facilitate SSR, allowing developers to create fast and SEO-friendly web applications by serving pre-rendered content to users.

Normalization is the process of organizing a database structure to minimize redundancy and dependency. By eliminating redundant data and storing related data in separate tables, normalization reduces storage space requirements and ensures data integrity, thus improving database efficiency.

The Transport layer ensures end-to-end communication reliability by segmenting data into smaller packets and reassembling them at the destination.

Partial dependency is a concept in database normalization where an attribute is functionally dependent on only a part of a composite primary key. In other words, it occurs when a non-key attribute depends on a subset of the primary key rather than the entire primary key. This can lead to data redundancy and anomalies in the database. By identifying and eliminating partial dependencies through normalization techniques like second normal form (2NF) and third normal form (3NF), databases can be structured more efficiently, reducing redundancy and ensuring data integrity.

The X-XSS-Protection header is used to mitigate Cross-Site Scripting (XSS) attacks in web applications. XSS attacks involve injecting malicious scripts into web pages, which can then execute in users' browsers, leading to data theft, session hijacking, and other security compromises. The X-XSS-Protection header instructs browsers to activate their built-in XSS protection mechanisms, such as filtering or blocking potentially dangerous scripts, thereby reducing the risk of successful XSS attacks. Implementing this header is an important security measure to safeguard against XSS vulnerabilities and protect users' sensitive information.

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.