Which among the following does not fall in the category of Morality Plays?

The correct option is: The City Heiress.

To understand why this is the correct answer, we can look at the characteristics of a Morality Play and examine each of the choices provided.

What is a Morality Play?
A Morality Play is a genre of medieval and early Tudor theatrical drama that was popular in the 15th and 16th centuries. These plays are allegories in which the protagonist (representing humanity as a whole) is met by personifications of various moral attributes, virtues, and vices (such as Mercy, Mischief, Good Deeds, or Pride) who battle for the protagonist's soul.

Analyzing the Options:
1. The Castell of Perseverance: This is one of the earliest, longest, and most structurally complete surviving English morality plays, dating from the early 15th century.
2. Mind, Will and Understanding: Also known as Wisdom, this is a late medieval morality play written around 1460–1463.
3. Mankind: Written around 1470, this is another highly popular medieval English morality play.
Together, these three works are famously grouped together and preserved in the Macro Manuscript (referred to as the "Macro Plays").

Why The City Heiress does not fit:
The City Heiress is a Restoration comedy written by the English playwright Aphra Behn and first performed in 1682. Rather than a medieval moral allegory dealing with the spiritual salvation of human souls, it is a satirical, politically charged comedy of intrigue set in 17th-century London. Therefore, it does not belong to the category of Morality Plays.