You need to create a centralized metadata connection to a database server for an application.

Comprehensive and Detailed Explanation:

To establish a centralized metadata connection to a database server in Talend Studio, follow these steps before constructing a Job that reads from the database:​

Create Db Connections Metadata to Describe the Database Connection (Option C):

In the Repository panel, right-click on "Metadata" and select "Create connection."​

Fill in the necessary details such as database type, host, port, database name, username, and password.​

Test the connection to ensure it is configured correctly.​

Save the connection metadata for reuse across multiple Jobs.​

Retrieve the Schemas from the Database Connection (Option E):

After creating the database connection metadata, expand it to view the available schemas.​

Retrieve the required schemas by importing the table structures.​

This step ensures that the schema definitions are centralized and can be reused in different Jobs.​

Drag the Db Connections Metadata onto the Designer to Read from the Database Component (Option D):

In the Repository, locate the previously created database connection metadata.​

Drag and drop the desired table or schema onto the Designer workspace.​

Talend Studio will automatically create the appropriate input component (e.g., tDBInput) configured with the connection and schema details.​

By following these steps, you ensure a centralized and consistent approach to managing database connections and schemas, promoting reusability and reducing configuration errors.​