Who did the Horatii fight against during the reign of Tullus Hostilius?

The Horatii fought against the Curiatii during the reign of Tullus Hostilius. This conflict is rooted in a legendary tale of early Roman history, where these two sets of triplet brothers engaged in a combat to settle a dispute between their respective cities, Rome and Alba Longa. The battle was intended to avoid a larger conflict and instead resolve the rivalry through a trial by combat. The Horatii emerged victorious, which solidified Rome's dominance over Alba Longa and marked a significant moment in Roman expansion. This story is emblematic of the Roman values of bravery and duty, showcasing the importance of individual valor in the service of the state. The other options do not pertain to this specific conflict involving the Horatii, making the Curiatii the only correct answer.