In Node.js, the commonly used package to connect to a MySQL database is mysql. This package provides a straightforward way to interact with MySQL databases, allowing you to establish connections and perform database operations. The other options are not standard packages for MySQL database connections.

The global object in a Node.js module is available only within the module where it is declared. It is not shared across all modules, and each module has its own isolated scope. The other options do not accurately describe the behavior of the Node.js global object.

Node.js uses Callbacks to achieve Non-Blocking I/O operations. When a task is completed, a callback function is executed, allowing Node.js to handle many connections simultaneously without blocking the execution of other tasks.

In Express.js, you can define middleware functions at both the application level and router level. These middleware functions can be used to handle different parts of the request-processing pipeline.

In Express.js, a catch-all or wildcard route is used to match any route that has not been matched by earlier routes. This is often used for creating custom error handlers or handling undefined routes.

You can pass data from your Express route handler to your EJS view using the res.render('view', dataObject); method. This method renders the EJS view and includes the data in the view template, making it accessible for rendering dynamic content. The other options are not valid ways to pass data to EJS views.

In the package.json file, the scripts property is used to define custom scripts that can be run using npm commands. This property allows you to define various scripts such as "start," "test," or custom scripts for tasks like building, linting, or deploying your application.

Using a CDN (Content Delivery Network) server is recommended in production environments to serve static files. CDNs distribute static assets across multiple servers located around the world, reducing latency and improving load times for users.

OAuth 2.0 is a standard protocol used for securing APIs. It allows you to implement authentication and authorization by issuing tokens to clients. These tokens can be used to access protected resources, making it an effective method for securing RESTful APIs in Express.js applications.

In Node.js, a 'end' event is emitted by a readable stream when there is no more data to read. This event is commonly used to signify the end of data reading operations from a readable stream. The other options (close, finish, complete) are not used in this context.