Which of the following is NOT a valid reason for denying a salesperson's license?

Having a valid Colorado driver's license is a necessary requirement for obtaining a salesperson's license, but it is not a valid reason for denying the license itself. This requirement is in place to ensure that the salesperson can legally operate vehicles and fulfill their responsibilities in the sales process.

In contrast, the other options reflect serious ethical and legal violations that directly impact the integrity of the automotive sales industry. Knowingly disposing of a stolen motor vehicle, defrauding a retail buyer, and misrepresenting a used vehicle as new are all actions that compromise consumer trust and violate laws that govern fair business practices. Engaging in any of these actions can result in legal repercussions and directly impacts the dealer's ability to operate ethically within the industry, making them valid grounds for denial of a salesperson's license.