You have a custom master page named MyApplication.master.

You need to apply MyApplication.master to only a custom application page in a SharePoint site. You must achieve the goal by using the minimum amount of effort.

What should you do?

A.
Add a custom HTTP module to the Web application that modifies the master page.

B.
Add a custom HTTP module to the Web application that modifies the custom application page.

C.
Set the MasterPageFile attribute to ~/_layouts/MyApplication.master in the @Page directive of the custom application page.

D.
Rename the custom application page as application.master and overwrite the default application.master page in the 14\TEMPLATE\LAYOUTS folder.

Explanation:
MNEMONIC RULE: “custom master page = MasterPageFile”

Using a Page Specific Master Page in SharePoint 2010
http://kjellsj.blogspot.com/2010/07/using-page-specific-master-page-in.html