Final answer:
Geoffrey Chaucer is the first truly great figure in English literature that we know much about, best known for 'The Canterbury Tales'.
Step-by-step explanation:
The first truly great figure in English literature that we know much about is A. Chaucer. Geoffrey Chaucer is renowned for his work 'The Canterbury Tales' which is a cornerstone of English literature and marks him as a pivotal figure of the Middle Ages.
Although B. Beowulf are the title character and work from an earlier period, the author is unknown. D. Bede, also known as the Venerable Bede, was an English monk and scholar whose work is of great historical importance, but his contributions are not primarily literary in the way Chaucer's are.
And while C. Shakespeare is arguably the most famous English playwright and poet, he came about two centuries after Chaucer, making Chaucer the first known great literary figure.