Classes that are both in the same assembly and derived from the declaring class.
Only methods that are in the same class as the method in question.
Internal methods can only be called using reflection.
Classes within the same assembly, and classes derived from the declaring class.
Encapsulating an object in a value type.
Encapsulating a copy of a value type in an object.
Encapsulating a copy of an object in a value type.
Encapsulating a value type in an object.
A DataSet can be synchronized with the database.
A DataSet can be synchronized with a RecordSet.
A DataSet can be converted to XML.
You can infer the schema from a DataSet.
The conversion of one type of object to another.
The runtime resolution of method calls.
The exposition of data.
The separation of interface and implementation.
Here's an interesting quiz for you.