Which religion first gained popularity as part of the roman empire in the 4th century

Christianity is the correct answer.

Explanation:

Christianity developed out of the Jewish tradition in the first century CE and later spread to the Roman empire. It was based on the teachings of Jesus and the works of Paul of Tarsus. In the beginning, it was a small unorganized sect which promised salvation after death. Christianity gained followers from Jewish communities and from throughout the Roman world.

In 313 CE the emperor Constantine issued the Edict of Milan, it granted legal status to Christianity.  The council of Nicaea was held in 325 and during which the Christian leaders decided the formal beliefs of Christianity and in 380 Ce emperor Theodosius issued the Edict of Thessalonica which made Christianity the official religion of the Roman Empire.

d. hip hop

it was originated in the 70s while the harlem renaissance occured in the 1920s