Which of the following characteristics of She Stoops to Conquer is not correct?

The correct option is: "It does not cast excellent characters."

To understand why this statement is incorrect, let us analyze the literary features of Oliver Goldsmith's famous 1773 play, She Stoops to Conquer:
1. Ingenious and lively plot: The play is celebrated for its fast-paced, complex plot involving mistaken identities, tricks (particularly Tony Lumpkin's deception), and romantic misunderstandings that keep the audience engaged and entertained.
2. Excellent characters: The assertion that the play "does not cast excellent characters" is false. She Stoops to Conquer is renowned precisely for its memorable, vibrant, and well-drawn characters. Figures like the mischievous Tony Lumpkin, the nervous Marlow (who is shy with high-born women but behaves differently with working-class women), and the resourceful Kate Hardcastle are classic, enduring characters in English comedy.
3. Vivacious and delightful style: Goldsmith uses a charming, witty, and humorous tone that contrasts sharply with the dry, moralizing sentimental comedies of his era.
4. Lack of Restoration grossness: While the play revived the laughing comedy style, it carefully avoided the overt vulgarity and cynicism (often referred to as "grossness") characteristic of Restoration comedies from the late 17th century, making it suitable for 18th-century sensibilities.

Therefore, the statement "It does not cast excellent characters" is the incorrect characteristic of the play, making it the correct option for this question.