The correct option is 'ORDER BY'. This clause is used to sort the result set returned by the SELECT statement in either ascending or descending order based on one or more columns. It helps the developer to retrieve records in a specific order as required. 

The DECLARE CURSOR statement is used to declare a cursor in DB2. This statement defines the result set for the cursor, specifying the SELECT statement that will be used to retrieve rows. Once declared, the cursor can be opened, fetched, and closed to process the rows returned by the associated query. 

Denormalization can lead to reduced query execution time as it reduces the need for complex joins and enables faster data retrieval. This can improve overall system performance and response times. 

Tags in DB2 serve the purpose of labeling and organizing database objects. They allow users to categorize and manage objects more efficiently, facilitating better organization and management of database resources. For example, tags can be used to group tables, views, or stored procedures that belong to a specific project or department. 

To verify the successful completion of the DB2 installation process, you can check for the db2setup.log file in the installation directory. This log file contains detailed information about the installation process, including any errors encountered. Checking this log ensures that the installation completed without issues. 

The DB2 Command Line Processor (CLP) provides a set of built-in commands that allow administrators to perform common administrative tasks programmatically, enabling automation. By leveraging scripting languages such as Bash or PowerShell, administrators can create scripts to automate routine database maintenance, backup and recovery operations, and performance monitoring tasks. This automation reduces manual effort, minimizes the risk of errors, and improves overall operational efficiency. 

The IMPORT utility in DB2 supports various common file formats such as CSV (Comma-Separated Values), fixed-width, and XML files. These formats are widely used for data interchange and are compatible with many external systems and applications. Using the IMPORT utility, users can efficiently load data from these file formats into DB2 tables, facilitating seamless integration and data exchange between different systems. 

The correct answer is option B. The configuration file containing database connection details in DB2 is named db2.ini. This file is located in the instance directory and holds various parameters for database connections. 

DB2 Visual Explain assists in identifying potential performance issues within queries, such as inefficient access paths or inadequate join strategies, which can then be addressed to enhance overall query performance. 

Denormalization can impact data integrity and consistency negatively as it may introduce data redundancy and inconsistency, making it more challenging to maintain data integrity and ensuring consistency across the database. 

Nesting tags in DB2 are significant because they help in organizing and structuring the data hierarchically. By nesting tags, you can represent complex relationships between different elements of the data, making it easier to understand and query. It allows for a more organized and intuitive representation of the data model within the XML document. 

IBM Data Studio provides various features like Query Tuner, Visual Explain, and Performance Optimization, which help in optimizing queries, analyzing execution plans, and improving overall database performance. It offers an Integrated Environment for managing database objects, monitoring performance, and debugging SQL statements, enhancing database administration tasks in DB2.