What design feature of elevator cabs helps to increase passenger comfort?

The design feature that significantly enhances passenger comfort in elevator cabs is the use of vibration dampening materials. These materials are incorporated into the cab structure to minimize vibrations and noise that can occur during travel. Reducing vibrations leads to a smoother ride, which is crucial in providing a comfortable experience for passengers. This is particularly important in high-rise buildings where elevators travel at greater speeds and may be more susceptible to movements that cause discomfort.

Other choices, while they may contribute to the overall experience, do not directly address the fundamental issues related to ride quality. Built-in lights, retractable seating, and automatic temperature control can improve visibility, seating comfort, and climate control, respectively, but they do not specifically target vibrations and the associated discomfort from an elevator's movement. Consequently, vibration dampening materials stand out as the most effective feature for enhancing the riding experience.