Final answer:
The 15th-century plays that feature a conflict between good and evil are known as Morality plays, which are allegorical dramas teaching moral lessons.
Step-by-step explanation:
The type of 15th-century play that features a conflict between good and evil is the B) Morality play. Morality plays are a form of allegorical drama that emerged during the medieval period, designed to teach moral lessons through the personification of moral concepts such as vice and virtue. A well-known example of a morality play is Everyman, where characters personify abstract qualities and engage in a narrative that teaches a lesson about life, death, and salvation.