Final answer:
The Valve's Orange Box package includes the game 'Portal,' which is famous for its unique puzzle-platform gameplay involving the creation of teleporting doorways. So, the correct answer is a) Portal.
Step-by-step explanation:
The student is asking about a game included in Valve's Orange Box package, which is known for containing a variety of popular video games.
The doorway-creating game included in this package is Portal.
This puzzle-platform game was released in 2007 and received acclaim for its unique gameplay, which involves solving puzzles through the creation of portals that allow the player to teleport between different locations within the game environment.
Therefore, the answer to the question is a) Portal.