The correct answer is were tortured
The Roman coliseum was a venue for festivities and shows for Roman civilians, and some Christians participated in these shows, being devoured by lions or killed in creative ways by gladiators.
It is important to note that during the first three centuries of the Christian era there were no Roman civilians who were Christians. They were all polytheists, and some Jews were prejudiced by ethnicity.
The Christians of that period lived in communities around Rome, as did the community of Jerusalem, Corinth, Antioch, Galatas, etc.
These communities did not participate in Roman social life, did not pay taxes, did not worship Cesar and did not work for the State, only for their communities.
For these reasons, Roman civilians saw Christians as outcasts, outlaws, people who hinder Roman social development, and thus, the Roman people themselves supported the persecution of Christians, and that their leaders died in shows at the Colosseum.