Answer:
The epitaph of Urbicus that "seems to confirm what is generally believed to have been the nature of gladiatorial combat during the imperial period" of ancient Roman society is likely to be:
b) It emphasizes the brutality of combat.
Gladiatorial combat during the Roman Empire was known for its brutality and often deadly nature. Gladiators were pitted against each other in a fight to the death, and the spectacle was meant to entertain the Roman populace. Emphasizing the brutality of combat in Urbicus's epitaph would align with the general understanding of the nature of gladiatorial combat in ancient Rome, where the goal was often to display the violent and lethal nature of the contests for the entertainment of the audience.