Object caching is recommended for frequently changing data in Entity Framework. It caches the results of query executions in memory, reducing the need to repeatedly access the database for the same data. However, it's important to manage the cache appropriately to ensure consistency and avoid stale data issues.

When using connection pooling, potential issues or challenges may include connection leaks, where connections are not properly closed and returned to the pool, leading to resource exhaustion. Deadlocks can occur when multiple threads contend for the same set of resources, causing performance degradation. Resource contention may arise when the pool size is insufficient to handle the application's workload, impacting scalability.

In Code-First development, you define the data model using entity classes. These classes represent the structure of your data and are used to interact with the underlying database tables.

Entity Framework supports Entity Splitting to map a single entity to multiple related tables. In this scenario, you can use Entity Splitting where one entity's properties are mapped to multiple tables. Each table in the database will correspond to a subset of the entity's properties, and Entity Framework will manage the mapping accordingly. This approach allows for better organization and management of data across multiple tables while maintaining relationships between them.

When executing a LINQ to Entities query, the ToList method is used to retrieve the results. It materializes the query and returns the results as a List collection.

ADO.NET Datasets allow you to work with data in a disconnected manner. This means that after retrieving data from the database, the connection to the database is closed, and the data is held in memory until it is either updated in the dataset or discarded.

LINQ to Objects is the appropriate choice for querying in-memory collections, such as lists of customer objects. It provides powerful querying capabilities against in-memory data structures.

Parameterized queries are a recommended practice to prevent SQL injection attacks. By using parameters, the values provided by users are treated as data rather than executable code, thereby mitigating the risk of injection attacks.

The correct option is Improved. Using a database-specific data provider, like SqlClient for SQL Server databases, often results in improved performance compared to generic providers such as OLEDB. This is because database-specific providers are optimized to leverage the features and capabilities of a particular database system, leading to better efficiency and resource utilization. Generic providers may introduce additional layers of abstraction and overhead, which can impact performance negatively.

To retrieve different data types from a data reader, you can use the GetValue() method. This method returns the value of the specified column as an object, which you can then cast to the appropriate data type based on the data stored in the database.