A pad in the main model cannot be hosted by topography in a Design Option [--if you continue it will not be added to the design option set].
Namespace: Autodesk.Revit.DB
Assembly: RevitAPI (in RevitAPI.dll) Version: 26.1.0.0 (26.1.0.34)
Syntax
C#
public static FailureDefinitionId ConfusingPadByElementsInDesignOption { get; }