Final answer:
A) Are not required to have spring brakes. Air brake equipped trailers made before 1975 are required to have spring brakes and the weight of a trailer does not affect its stopping ability. Older trailers may need a glad hand converter, but this can vary depending on the specific trailer and tractor unit.
Step-by-step explanation:
Air brake equipped trailers made before 1975 are required to have spring brakes. Spring brakes are a safety feature that applies the brakes automatically if the air pressure is lost, helping to prevent accidents. Therefore, option A) in the question is incorrect.
Regarding option B), the weight of a trailer does not affect its stopping ability. It is the design and braking system that determine how easy or difficult it is to stop. Newer trailers may have advances in braking technology that make them easier to stop, but weight alone does not determine this.
Option C) states that older trailers usually need a glad hand converter. A glad hand converter is a device used to bridge the gap between old-style air brake systems and newer tractor units. It allows a newer tractor unit to connect to and control the air brakes of an older trailer. However, the need for a glad hand converter may vary depending on the specific trailer and tractor unit.