Salesforce JavaScript Developer Practice Exam

The code that must be added to receive incoming request data in a Node.js HTTPS server uses the event-driven architecture of Node.js. By utilizing `req.on('data', (chunk) => { ... })`, the server sets up an event listener for the 'data' event. This event is emitted whenever a chunk of data is available from the incoming request stream. Each chunk of data can be processed as it arrives, allowing for efficient handling of large data streams without having to wait for the entire request to finish before beginning processing.

This approach is essential for handling data in a non-blocking manner, which is a key feature of Node.js. The server can continue to perform other operations while it listens for incoming data, ensuring better performance and responsiveness.

Other choices do not conform to the correct syntax or event structure used in Node.js for processing incoming data streams. They either misuse method names or event types that do not exist or are incorrectly structured for handling streams in this context.