NoSQL databases offer schema flexibility, allowing developers to store and manage unstructured or semi-structured data without predefined schemas. This flexibility is advantageous in scenarios where the data model is evolving or where dealing with highly variable data types. Unlike traditional relational databases that enforce a strict schema, NoSQL databases can adapt to changing data requirements, making them more scalable and agile in certain use cases.

SFTP (SSH File Transfer Protocol) is recommended for secure file transfers because it encrypts both authentication information and data being transferred. This ensures that sensitive files are protected from unauthorized access during transmission. FTPS also provides secure file transfer, but it requires additional configurations such as SSL certificates, making it more complex to set up and maintain compared to SFTP. HTTPS is primarily used for secure web communications, not file transfers. AS2 is a protocol specifically designed for secure and reliable data interchange over the Internet, but it may not be as commonly implemented as SFTP for general file transfers within an organization.

Updating DNS records with the correct information is crucial for resolving DNS-related issues that make a website unreachable. This involves accessing the domain registrar or DNS provider's control panel and ensuring that the DNS records (such as A records, CNAME records) are correctly configured to point to the website's hosting server. Checking the DNS configuration on the server helps identify any misconfigurations or discrepancies. Flushing the DNS cache on the client can resolve cached DNS issues but doesn't address incorrect DNS records directly. Testing connectivity using nslookup is a diagnostic step to verify DNS resolution, but it alone does not fix the incorrect records.

NoSQL databases come in various types, each designed for specific data handling needs. Document-oriented databases like MongoDB store data in flexible, JSON-like documents, while key-value stores like Redis use simple key-value pairs. Columnar databases such as Cassandra organize data in columns rather than rows. Graph databases like Neo4j focus on relationships between data entities. Understanding these differences helps in choosing the right database for specific use cases.

Option 2: The default branch name in Git has evolved; historically, it was often 'master,' but newer conventions use 'main.' This is the branch where development typically begins and where stable versions are merged.

Query execution plans show how a database will execute a query, helping to identify inefficient operations and suggesting improvements such as index usage. This insight is crucial for optimizing database queries and improving overall performance.

The time complexity of the binary search algorithm is O(log n), where n is the number of elements in the sorted array. This efficiency is due to the algorithm halving the search space in each step.

Bluetooth is the wireless technology commonly used for short-range communication between devices like smartphones and smartwatches. It operates on the 2.4 GHz frequency band and is known for its low power consumption.

The quantum time, also known as time slice or time quantum, is the maximum amount of time a process can execute before being interrupted in preemptive scheduling algorithms like Round Robin. It defines the length of each time slot during which a process can run before the scheduler switches to another process.

JSX (JavaScript XML) is a syntax extension used in React for writing HTML-like code within JavaScript. It allows developers to create React components more elegantly and expressively. While TypeScript, Webpack, and Babel are all crucial tools in the React ecosystem, JSX stands out as the correct answer because it directly relates to React's unique approach to building user interfaces with a blend of JavaScript and HTML-like syntax.