This .NET class wraps the AcDbMText ObjectARX class. 

The MText class represents the MTEXT entity type within AutoCAD. 

An MTEXT object is a multiline text entity that stores a specified line width and performs automatic word wrap to keep the text within this width boundary.

Autodesk.AutoCAD.DatabaseServices.DBObject
    Autodesk.AutoCAD.DatabaseServices.Entity
        Autodesk.AutoCAD.DatabaseServices.MText

Public Class MText
Inherits Entity

public class MText : Entity;

• Each change to an MText object can cause the text contents to be reformatted. On larger objects, this can be a time-consuming operation. To prevent this reformatting, make any MText.Contents call the last operation before closing the object.
• Rotation works with the current UCS normal in the AutoCAD editor and the object coordinate system (formerly known as the ECS) associated with this normal. The value that this property sets is actually the MText direction. The Direction property (which deals with a WCS vector) is a much more direct and less confusing way to get the same result.