Answer:
B. A contrivance
Step-by-step explanation:
A plot contrivance is an event in a narrative that is extremely unlikely to happen, but that is still technically possible. In this case, the readers have no reason to think that Miguel would suddenly change his mind and destroy the shop. Therefore, although technically possible, the event is not realistic. A narrative that is full of plot contrivances is usually of bad quality, as it lacks a realistic plot and character development.