What is a key characteristic of the rope used in personal escape systems?

A key characteristic of the rope used in personal escape systems is its heat resistant sheathing. This quality is crucial because escape situations often occur in environments with elevated temperatures or exposure to fire. Heat resistant materials help ensure the integrity and safety of the rope, preventing it from melting or degrading when subjected to high heat, which could compromise the escape system and endanger the user.

Options that mention cotton for comfort, fluorescent color for visibility, or elasticity for flexibility do not address the primary functional requirements of a personal escape system. While visibility and comfort may be factors in some applications, they do not provide the necessary protection against heat that is vital during fire events, which is the primary purpose of using heat resistant materials. Additionally, while some degree of flexibility is advantageous in rope design, it is not as critical as the rope's ability to withstand high temperatures during an emergency.