Abrupt changes in elevation of walking surfaces in the means of egress must not exceed which of the following?

The requirement for abrupt changes in elevation of walking surfaces in means of egress is primarily focused on ensuring safety and accessibility for all individuals, including those with mobility impairments. A change of more than 1/4 inch can create a tripping hazard, especially in high-traffic areas like egress paths that are used during an emergency.

The guideline that limits these abrupt changes to 1/4 inch aligns with the standards set forth in the Americans with Disabilities Act (ADA) and various building codes, which prioritize smooth transitions and continuity in walking surfaces. Maintaining this limit helps ensure that individuals can navigate exits safely and effectively, reducing the risk of injury.

Therefore, the correct answer reflects the best practice for designing accessible and safe egress routes, emphasizing the need for careful consideration of surface transitions in these critical areas.