The correct option is "Transmission Control Protocol." TCP stands for Transmission Control Protocol, which is one of the core protocols in the TCP/IP suite. It provides reliable, connection-oriented communication between devices over a network. TCP ensures data integrity, sequencing, and flow control during data transmission, making it a fundamental protocol for applications that require reliable data delivery.

A VPN (Virtual Private Network) enhances security for remote users by encrypting data, preventing unauthorized interception. It also provides secure access to internal resources, allowing remote workers to connect securely to their organization's network. Additionally, a VPN masks the user's IP address, adding a layer of anonymity, and uses tunneling protocols to ensure secure communication over the internet. These combined features significantly enhance network security for remote users.

Threads typically use less memory compared to processes because they share the same address space and resources like code and data sections. Processes, on the other hand, have their own memory space and require more overhead for context switching and resource allocation.

Option 4 suggests using a memory pool-based linked list, which optimizes memory usage by pre-allocating nodes from a fixed-size pool. This approach reduces the overhead of frequent memory allocations and deallocations, improving efficiency in a memory-constrained environment.

Top-down DP involves starting from the top (the initial problem) and breaking it down into smaller subproblems, storing solutions to these subproblems in a table (memoization). Bottom-up DP, on the other hand, starts from the bottom (solving the smallest subproblems first) and builds its way up to solve the larger problem using a table (tabulation). While top-down uses recursion and memoization, bottom-up uses iteration and tabulation.

Web application firewalls (WAFs) primarily filter incoming requests. These requests include HTTP and HTTPS traffic, allowing the firewall to analyze and block potentially malicious requests before they reach the web application. This helps protect against common web-based attacks like SQL injection, cross-site scripting (XSS), and command injection.

Round Robin scheduling algorithm provides better response time for interactive processes because it ensures that each process gets a fair share of CPU time. By using time slices, it prevents any single process from monopolizing the CPU, which is important for maintaining system responsiveness, especially in interactive environments where users expect quick feedback.

In JavaScript, objects are accessed using the dot notation, where the object name is followed by a dot and then the property or method name. Therefore, the correct option here is "Object," as it directly represents the entity accessed using dot notation in JavaScript. This concept is fundamental to understanding how to work with objects in the language.

First Fit is a memory allocation algorithm where the operating system allocates the first available partition that is large enough to fit a process's memory requirements. It divides memory into equal-sized partitions and searches for a suitable partition starting from the beginning of the memory. Although it may lead to fragmentation, it is easy to implement and requires minimal bookkeeping overhead.

A Directory Entry is a data structure in a file system that associates file names with their respective inodes, enabling the operating system to locate files based on their names.