Final answer:
The noble gas that could require the attention of a Registered Nurse due to overexposure, and has the atomic number 86, is Radon (d). It is radioactive and exposure to it is linked to a higher risk of lung cancer.
Step-by-step explanation:
You might need an RN (Registered Nurse) if you're exposed to too much radon, which is the noble gas with the atomic number 86. Therefore, the answer to the question is d) Radon. Radon is an invisible, odorless noble gas that is released from the ground and is radioactive. Exposure to radon has been correlated with an increased risk of lung cancer. Unlike neon, which is used in neon lights, or argon, which is often used as an inert atmosphere for welding and in light bulbs, radon's potential health risks make it particularly noteworthy in the context of health and safety.