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.

The operation in queues that removes an element from the front is called dequeue. Dequeue removes the element that has been in the queue the longest, following the First In, First Out (FIFO) principle. This operation is essential for processing data in the order it was received, such as handling tasks in a computer's task queue or managing requests in a web server's request queue.

Database normalization aims to eliminate Functional Redundancy, where the same piece of data is stored in multiple places, leading to inconsistencies and potential data integrity issues.

useState is a React hook that allows functional components to manage state locally. It simplifies state management within a component without the need for class-based components or external libraries like Redux. The other options are also valid for state management, but useState is specifically designed for component-level state management and is a fundamental part of React's modern approach to state handling.

When one thread waits for another to complete its execution, it's termed synchronization. This can involve mechanisms like joining threads or using synchronization primitives like mutexes or semaphores. Suspension refers to temporarily halting a thread's execution, threading is a general term for working with threads, and blocking describes a state where a thread is waiting for an event or resource to become available.