It is custom of Christianity to sing morning prayer in the church regularly.

Answer: Option B

One word substitute is Matin.

Epilogue: a section or speech at the end of a book or play that serves as a comment on or a conclusion to what has happened.
Matin: a Christian service of morning prayer, especially in the Anglican Church.
Epitaph: a phrase or form of words written in memory of a person who has died, especially as an inscription on a tombstone.
Vesper: evening prayer; vespers.