Final answer:
The first substantive contact is when a prospective purchaser walks into a real estate office, meets with an agent, and discusses the purchase of a specific property. Other options do not involve significant discussions about a potential transaction.
Step-by-step explanation:
The first substantive contact in this scenario is option c. A prospective purchaser walking into a real estate office, meeting with an agent, and discussing the purchase of a specific property.
Substantive contact refers to a meaningful or significant interaction between the licensee and the prospective seller or buyer, where they engage in discussions about a potential real estate transaction. In this case, meeting with an agent and discussing the purchase of a specific property demonstrates the intention and seriousness of the prospective purchaser.
Options a, b, and d do not meet the criteria for the first substantive contact as they involve casual inquiries or non-personal interactions that do not entail significant discussions about a potential transaction.