The "Optimal Substructure" property in dynamic programming states that the optimal solution to a problem can be constructed from optimal solutions to its subproblems. This property enables subproblems to be solved independently and then combined to solve the overall problem efficiently.

ARP stands for Address Resolution Protocol. ARP is a communication protocol used for discovering the link layer address (MAC address) of a network host. It translates an IP address into a MAC address and is essential for communication between devices on the same network. A protocol is a set of rules governing data transmission, making "Protocol" the correct option here.

The "I" in ACID stands for Isolation. This property ensures that each transaction is isolated from other transactions until it is completed, preventing interference and ensuring data integrity during concurrent transactions.

The == operator in JavaScript checks for value equality without considering the data type, whereas the === operator checks for both value and type equality. This distinction is crucial in ensuring accurate comparisons in JavaScript.

The Domain Name System (DNS) protocol is used for resolving domain names to IP addresses. When a user enters a domain name (like www.example.com) into a web browser, the DNS system translates this domain name into an IP address that the computer can use to connect to the corresponding web server. This process is essential for navigating the internet, as it allows users to access websites using human-readable domain names rather than remembering complex IP addresses.

Caching in RESTful APIs refers to storing frequently accessed responses so that they can be quickly retrieved without re-executing the entire request. This reduces server load by serving cached responses instead of processing requests repeatedly. It speeds up data retrieval by providing quick access to pre-generated responses, minimizing the time taken to fetch data from databases or external services. Caching also helps minimize network latency as cached responses are served closer to the client, reducing the round-trip time for data transmission. However, caching doesn't directly relate to data encryption; it focuses on improving response time and reducing server overhead.

MIMO involves using multiple antennas for both transmitting and receiving data, improving performance by increasing throughput, reliability, reducing latency, and enhancing coverage.

OSPF (Open Shortest Path First) is commonly used within an Autonomous System (AS) due to its advanced features such as fast convergence, scalability, and support for variable-length subnet masking (VLSM).

The correct option is URI. In RESTful APIs, Uniform Resource Identifiers (URIs) are used to uniquely identify and represent resources. URIs play a crucial role in REST architecture by providing a way to interact with resources via HTTP methods such as GET, POST, PUT, and DELETE.

Breadth-first search (BFS) explores nodes level by level starting from the root node, using a queue to keep track of nodes to be visited. On the other hand, depth-first search (DFS) explores nodes depth-wise, going as far as possible along a branch before backtracking, typically using a stack to keep track of nodes. This fundamental difference in traversal order distinguishes BFS from DFS in graph traversal.