A non-removable means must be provided to prevent a LULA's car downward movement at a height of ___________ to __________ inches above the pit floor.

The requirement that a non-removable means must be provided to prevent a LULA (Limited Use, Limited Access) elevator's car from moving downward at a specified height relates to safety measures designed to protect users who may have mobility challenges. The range of 35 to 79 inches above the pit floor indicates a span that includes points commonly encountered by users, especially those in wheelchairs or with assistive devices.

This specific range is established in safety codes, including those from the American Society of Mechanical Engineers (ASME) and other regulatory bodies, to ensure that any potential hazards of a downward-moving elevator are mitigated within the typical reach or headspace of the people using the elevator—ensuring that the system's design is inclusive and accessible.

Other ranges provided in the options may either exceed the upper limit or fall below the minimum requirement specified by industry standards, making them inappropriate for compliance with safety regulations for LULA installations. Thus, the choice of 35 to 79 inches reflects the necessary safety consideration for protecting users from unintended elevator movement at accessible heights.