Final answer:
An illegal nonconforming use refers to a property owner using their land for a purpose not permitted by current zoning laws.
Step-by-step explanation:
An illegal nonconforming use refers to a property owner using their land for a purpose not permitted by current zoning laws. Therefore, the most likely situation to represent an illegal nonconforming use is option a) A property owner using their land for a purpose not permitted by current zoning laws.