Final answer:
Caedmon was able to compose religious songs about Bible stories and God, as recounted by Bede, but could not compose vain or idle songs. Option a) is the correct answer.
Step-by-step explanation:
The kind of songs Caedmon was able to compose were specifically about Bible stories and God. According to the historical record, particularly the work by the monk Bededominated categories, known as 'The Ecclesiastical History of the English People', Caedmon was not able to compose songs that were considered vain or idle. This means that Caedmon's scope for songwriting was limited to religious themes, and he did not engage in creating songs about profane subjects or those that didn't serve a spiritual purpose.
Option a) is the correct answer: Caedmon was able to compose songs about Bible stories and God. He was not able to compose songs that were vain or idle. This reflects the story of Caedmon's miraculous gift for song that was recounted by Bede, where Caedmon, an unlettered cowherd, was said to have been bestowed with the divine ability to sing praises to God, but unable to sing secular compositions.