A narrative composed in the form of a letter is

Step 1: Analyze the question The question asks for the term describing a narrative written in the form of letters.

Step 2: Explain the concepts

• Eponymous novel: A novel named after its main character, e.g. Oliver Twist or Emma. The name comes from the title, not the form.
• Epistolary novel: A novel told through letters (and sometimes diary entries or documents). The word comes from the Greek epistole, meaning "letter".
• Novella: A short novel, longer than a short story but shorter than a full novel.
• Panegyric: A speech or piece of writing that praises a person or achievement.

Step 3: Match the definition to the options

• A narrative composed as a letter points to the epistolary form.
• A is about the title, C is about length, and D is about praise, so none of them fit.

A well-known example is So Long a Letter by Mariama Bâ, where the narrator, Ramatoulaye, writes a long letter to her friend Aissatou. It is a common text in West African literature studies.

Step 4: Answer The correct option is B. an epistolary novel.

Tip: Link "epistolary" with "epistle", the letters in the Bible such as the Epistles of Paul. If you see "letter" in a literature question, think epistolary.