Explanation: While Nero did persecute Christians at this time, he is only noted as having done so in the city of Rome itself, and on (almost certainly false) charges of arson rather than for their beliefs, specifically. Christianity is not recorded as having been banned or outlawed at that time. Christianity would not specifically be outlawed until ~300 AD, and then only for a few years.
Other Roman Emperors sometimes persecuted Christians intermittently, but generally on matters of practice rather than belief (the constant sticking point being swearing loyalty oaths to the Res Publica by Roman gods, or, related, making sacrifices to the gods on behalf of the Emperor), and ad hoc rather than systemically outlawing the sect.
