Final answer:
The Nova Scotia Real Estate Trading Act is a regulation governing the real estate business in Nova Scotia and thus falls under the Real Estate category.
Step-by-step explanation:
The Nova Scotia Real Estate Trading Act is legislation that governs the real estate industry in Nova Scotia. This act regulates how real estate trading is conducted in the province, including the licensing and conduct of real estate agents. The appropriate business category for the Nova Scotia Real Estate Trading Act is b) Real Estate, as it directly pertains to the practices, regulations, and ethical guidelines within the real estate industry.