Final answer:
Seller A has an obligation to disclose the addition of the unpermitted deck when selling her house, which can lead to legal consequences.
Step-by-step explanation:
Seller A has an obligation to disclose the addition of the deck to potential buyers when she decides to sell her house. While building permit requirements vary depending on local regulations, it is common for unpermitted structures to be considered violations of building codes. If the deck is discovered to be unpermitted during an inspection or after the sale, it can lead to legal consequences or complications for Seller A.