Which approach should you recommend?

You are designing a SharePoint 2010 application to manage projects. The application has the following
requirements:
Users must have access to the CreateProject.aspx page.
.All changes to the CreateProject.aspx page must be reflected on all project sites.
You need to design a page that can be accessed from each project site.
Which approach should you recommend?

A.
Create a master page and deploy it to the _layouts directory.

B.
Create a master page and deploy it to the _master pages directory.

C.
Create an application page and deploy it to the _layouts directory.

D.
Create an application page and deploy it to the Pages library.