Answer:
B. the fact that they are the largest surviving collection of 15th-century correspondence.
Step-by-step explanation:
Paston Letters, the largest surviving collection of 15th-century English correspondence. These letters are essential to historians and as well, philologists and is preserved mainly in the British Museum. Some of it was gotten from the circle of the career soldier Sir John Fastolf between 1378 and 1459, while some other parts of it, was derived from the records of the Paston family, Fastolf’s neighbours in eastern Norfolk.
These letters serves as ample evidence on matters relating to social, cultural, political, legal, religious and economic issues of Medieval England.
Also, they are important to the history of the English language as they are written in the language of the era which was quite different from Modern English.