The other answer to this question said that the answer was D Catacomb. This statement is incorrect, the definition pf catacomb is as follows:
cat·a·comb
ˈkadəˌkōm/
noun
an underground cemetery consisting of a subterranean gallery with recesses for tombs, as constructed by the ancient Romans.
The correct answer is Epistle, the definition is as follows:
e·pis·tle
əˈpisəl
nounformal
a letter.
synonyms: letter, missive, communication, dispatch, note, line;