Plan an adaptive UI layout

You are creating an ASP.NET MVC web application, and you decide to create a new layout for mobile devices with relatively small screens. Which @media query should you create or modify to accomplish the task? (Choose all that apply)

@media (max-width:478px) and (orientation:portrait)
@media (min-width:1200px)
@media (max-width:768px)
@media (min-width:768px) and (orientation:portrait)