Which of the following actions is required of licensed dealers?

Maintaining a retail location during business hours is a critical requirement for licensed dealers as it establishes a legitimate business presence in the community. This requirement ensures that consumers have a physical location to visit for inquiries, view vehicles, and complete transactions. It also contributes to transparency and accountability within the dealership industry, as customers can physically verify the dealer's operations and ensure they are dealing with a legitimate business source.

The other options, while related to automotive sales operations, do not reflect the essential requirements for maintaining a dealer's license. For instance, although inspecting vehicles is a good practice, it is not a mandated action for all dealers in Colorado. Similarly, purchasing from certified manufacturers is not universally required, as dealers often have the flexibility to acquire vehicles from various sources, including auctions or private sales. Conducting background checks on customers is also not a strict requirement, although it is a practice that some dealers may choose to implement for their own security and due diligence. Thus, maintaining a retail location is the primary requirement that solidifies the dealer's operational legitimacy.