What is the name of a long letter like the ones paul wrote to the people he had converted, answering their questions and settling problems?

a.
covenant

b.
torah

c.
epistle

d.
catacomb

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;

cause you are attracted to the features of girls or if you are a boy you are attracted to the features of a boy.

can you explain it better