Answer:
The feature of a comedy of manners present in the passage is mistaken identity.
Step-by-step explanation:
The dialogue between Algernon and Jack revolves around a misunderstanding regarding Jack's name, with Algernon insisting that it is Ernest and Jack denying it. This confusion over identity is a common theme in comedies of manners, which often involve characters adopting false identities or pretending to be someone they're not in order to gain an advantage or avoid social awkwardness. The use of mistaken identity in this passage also serves to create humor and irony, as Algernon's insistence that Jack's name is Ernest is at odds with the truth and leads to a comical argument between the two characters.