Topic 3, Scenario 3
Background
You are developing a service that allows for the direct digital-to-digital data conversion of one
encoding to another. Users currently employs the service for the uploading of audiovisual media
files for conversion to different formats, as well as for the viewing of the converted files.
Business Requirements
The client-side section of the application has been created as an ASP.NET MVC application using
Visual Studio 2012. The client-side of the application allows for the uploading of audiovisual media
and the planning of transcoding by administrators. Furthermore, administrators and users are
allowed to download the audiovisual medias that have gone through the direct digital-to-digital
data conversion process.
Metadata is attached to uploaded audiovisual medias for identification purposes. As soon as the
audiovisual media upload is complete, this metadata is collected by a single system.
User computers must have Microsoft Internet Explorer 7 installed, as a minimum.
The application excludes a header that can be viewed on all pages. The header has been
configured to display links to administrative functions for users logged in as administrators. A
cookie, which is configured on the server, supplies this data. In the event of an error condition
existing, the administrative links should not be displayed.
Technical Requirements
User Experience:
Users are able to scrutinize a list of audiovisual medias via the front-end web application. The
presented page is configured as the application’s principal view. Every request causes the HTML
elements, other than the list of audiovisual medias, to change. This, in turn, causes the page to
reload.
Compatibility:
Some user browsers, which do not support the HTTP DELETE verb, sends a POST request with
an HTTP header of X-Delete when the expected operation is to delete.
Transcoding:
A set of Windows Azure worker roles has been configured for transcoding purposes. A third-party
command line tool must be installed for transcoding. The path to the utility is hosted by an
Environment variable, subsequent to tool installation. The license key is included in a variable,
named license. When the utility is not in use, it has to be unregistered. Furthermore, a substantial
quantity of resources is consumed by the utility.
At any given time, the utility can have ten instances of the utility running, at most. An instance of
the role must allow other roles to process the additional audiovisual media that it cannot.
Errors are logged to a Logs directory under the utilities path by the utility.
Performance information is collected by a local Azure directory resource, named perf.
Development:
Errors generated by the utility must be examined by developers via Microsoft Remote Desktop
Protocol (RDP). This functionality has been provided by the creation of an x509 certificate that has
been distributed to the developers. Only RDP must be used by developers for this function.
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You have been instructed to maximize performance for users who download audiovisual media via

HTTP clients that support different content encodings by configuring caching on the
DownloadAudiovisualMedia action.
You want to write code to include the necessary attribute.
Which of the following is a property that should be included in your code?

A.
The VaryByControl property.

B.
The VaryByCustom property.

C.
The VaryByHeader property.

D.
The VaryByParam property.

E.
The VaryByContentEncoding property.