Answer Description: “<%@ WebService Language="VB" CodeBehind="~/App_Code/Service.vb" Class="Service" %>” is valid because it used to specify that code behind class belongs to same assemblies. “<%@ WebService Language="VB" CodeBehind="~/App_Code/Service.vb" Class="Service, AnotherAssemblies" %>” is valid because it used to spacify that code behined class belongs to different assemblies.