Which activity is an example of real estate supply activities?

Real estate supply activities refer to the processes involved in supplying properties to the market for sale or rent. Option A, advertising a property for sale, is an example of a real estate demand activity, as it aims to attract potential buyers or tenants. Option B, showing properties to potential buyers, is also a demand activity, as it involves the process of presenting properties to clients who are interested in buying or renting. Option C, negotiating a sale, is a part of the sales process and not specifically related to real estate. Option D, completing transaction paperwork, involves fulfilling all legal requirements and finalizing the sale or rental of a property, making it the correct answer as it is a crucial step in the supply process.