Which document is necessary to transfer title in Colorado?

Answer: B — completed title application form

In Colorado, the correct document necessary to transfer title is a completed title application form. This form serves as the official request to transfer ownership of the vehicle from the seller to the buyer. When a vehicle is sold, the seller must complete and sign the title, and the buyer then submits this title along with the title application form to the Colorado Department of Revenue or the local county clerk's office to effectuate the title transfer. Other options, while potentially useful in various circumstances, do not fulfill the formal requirements for title transfer. A notarial letter from the previous owner is not an officially recognized document for transferring title. An original purchase invoice is generally not needed for title transfer but may be necessary for proof of ownership in certain situations. Similarly, a temporary registration document does not constitute a title transfer; it may allow the vehicle to be legally used on the road for a limited time but does not change ownership records.