This question is based on General Literary Principles. A literary work that teaches moral is said to be

Step 1: Analyze the question The question asks for the literary term for a work whose purpose is to teach a moral lesson.

Step 2: Explain the concept The word didactic comes from the Greek didaskein, meaning "to teach." A didactic work is written mainly to instruct or to convey a moral, ethical, or religious lesson. Examples include fables, parables, proverbs, and morality plays. Many Nigerian folktales that end with "the moral of the story is..." are didactic.

Step 3: Examine the options

• A. Didactic: This is the correct technical term for literature that teaches morals.
• B. Instructive: This is an ordinary English word meaning "informative." It is not a literary term, and it doesn't specifically imply moral teaching.
• C. Corrective: This describes something that fixes errors. It is not a standard term for classifying literature.
• D. Impressive: This means something that leaves a strong impression. It has nothing to do with moral teaching.

Step 4: Answer The correct option is A. didactic.

Tip: Link didactic with "teach". If a JAMB question mentions a work that teaches, instructs, or preaches morals, think didactic. Don't confuse it with satire, which mocks vices to correct them, or allegory, which uses symbols to carry a deeper meaning.