What specific type of reflector must 1966 and later vehicles have?

For vehicles manufactured in 1966 and later, the requirement for reflectors is specifically that they must have two red reflectors on each side. This regulation is in place to enhance the visibility of the vehicle to other road users, especially at night or in low-light conditions. Red is universally recognized as a color associated with warning and danger, making it an effective choice for reflectors that ensure safety on the road.

The requirement for two reflectors on each side also helps to provide a more consistent visual signal for other drivers, enhancing the awareness of their presence. This is particularly important for the safety of both the vehicle occupants and other road users, as increased visibility reduces the likelihood of accidents. The other options presented do not align with these specific safety standards and regulations for vehicle reflectors established for vehicles from that era, thus reinforcing why the correct choice is two red reflectors on each side.