Final answer:
Roderick Usher faces struggles with the idea of death and decay, as well as isolation and fear. The story's use of mirror imagery supports these themes by reflecting Usher's internal struggle with the grim reality of life's inevitability.
Step-by-step explanation:
Roderick Usher appears to be facing multiple internal struggles in Edgar Allan Poe's narrative. The descriptions provided in the story suggest that Usher is dealing with Option 2: struggling with the idea of death and decay, and Option 3: battling with a sense of isolation and fear. His house, symbolic of his own mental state, is depicted as a once vibrant place that has now lost its vitality. This reflection of the physical into the psychological indicates a deep introspection and horror about the inevitable decay of life and the accompanying isolation.
Additionally, there is a strong sense of fatalism imbued in the text, as the reflections in the story serve to amplify the themes of hopelessness and darkness. It is clear that Poe uses mirror images or reflections to examine Usher's internal conflict with his grim circumstances and the dread of death. The gloomy setting, alongside the mirror images, including Roderick mirroring his sister and the house reflecting the tarn, help us reach the conclusion that Usher's true battle is a philosophical and psychological confrontation with the human condition and its eventual demise.