Analysis. Answer option E is correct.
The customErrors element provides information about custom error messages for ASP.NET applications. The mode attribute of the customErrors element specifies whether custom errors are enabled, disabled, or shown only to remote clients. Since Martin wants all applications to display a single error message, he should set the mode attribute of the customErrors element in the Machine.config file to On and remove the customErrors element from the Web.config file for App1.
== What is Machine.config==
Machine.config is a configuration file that includes settings specific to a
computer, such as built-in remoting channels, machine-wide assembly binding,
and ASP.NET configuration settings. The configuration system first searches
for APIs and ASP.NET settings in Machine.config. It then looks in the application
configuration file.
== What is Web.config==
Web.config is an XML file that consists of a series of settings specific to
an application. Whenever a new Web service project is created in Visual Studio
.Net, the Web.config file is automatically created and added to the project.
It contains a number of empty settings with text explaining each section and
its use.
Answer options C and B are incorrect. The Web.config file includes application specific settings.
Answer options A and F are incorrect. Error messages are customized using Web.config or Machine.config, and not App1.config.
Answer option D is incorrect. Setting the mode attribute of the customErrors element to RemoteOnly specifies that custom errors are shown only to remote clients and ASP.NET errors are shown to the local host.
Reference: Visual Studio .NET Combined Collection, Contents: "Machine.config", "Web.config", "<customErrors> Element"
