The paragraph contains several errors in parallelism. Decide if the selection in bold needs to be revised or if it is correct as is. Housed at Trinity University in Dublin and it is encased in a protective display cabinet, the Book of Kells is the astoundingly beautiful product of Irish monks who worked from the seventh century and they ended in the ninth century. The work is a codex, a bound book, that contains the four gospels of the New Testament. In addition, the gospels are prefaced with listings of Hebrew names, canon tables or concordances for the gospels are found, it has brief summaries of the gospels, and explanations of the four evangelists who wrote the gospels: Matthew, Mark, Luke, and John the Evangelist. The text is written in Latin, and the writers based it on the Vulgate of Saint Jerome, completed in AD 384. The book is one of many products of the widespread and what was a highly successful monastic presence in Ireland, which began with the arrival of Saint Patrick in the fourth century and many other Irish missionaries arrived in the fifth. The date and place of origin of the Book of Kells are still debated, but two locations, Iona and another named Kells, both associated with Saint Colum Cille, are believed to be the likeliest choices. Saint Colum Cille founded a monastery at Iona, an island off western Scotland, around 561, but later a house of refuge at Kells in county Meath, Ireland, was created by his order in 807, after Viking raids endangered the site at Iona. The Book of Kells was most likely written during the time of the migration. Which option below would be an acceptable revision of the selection in bold? a. who worked from the seventh century to the ninth century.
b. no revision is necessary.
c. who worked in the seventh century and they ended in the ninth century.
d. who worked from the seventh century and ended in the ninth century.