Which of the following controls located in accessible spaces must be accessible for occupant use?

In the context of accessible design, it is essential that controls located in spaces meant for occupant use allow all individuals, including those with disabilities, to interact with them comfortably and safely. This includes lighting switches, ventilation switches, and electrical convenience outlets.

Lighting switches must be positioned within reach and be operable with one hand, so that individuals with mobility challenges can easily access and use them. Similarly, ventilation switches should be placed at heights accessible to all users, ensuring that everyone can control the air quality in their environment. Electrical convenience outlets are also critical, as they provide access to power for various devices and equipment; their placement must accommodate those with different ranges of motion.

Therefore, since all these controls—lighting switches, ventilation switches, and electrical convenience outlets—must be accessible for occupant use, the correct answer encompasses all these elements, which is why it is stated as D. This comprehensive approach ensures that spaces are usable by the widest range of individuals, aligning with accessibility standards and building codes designed to promote inclusivity.