The playwright develops the mood in this scene by creating a calm atmosphere at the beginning when Nolan approaches the officers and shows interest in their reading. However, as the scene progresses and the context of Nolan's situation—having been denied news of his homeland and the emotional toll it takes on him—is revealed, the mood becomes sorrowful. Therefore, the correct answer is:
The mood is calm in the beginning of the scene, but as the scene goes on the mood becomes sorrowful.