Final answer:
Neon (A) is the noble gas among the options provided. It belongs to Group 18 and is used in lighting systems.
Step-by-step explanation:
The noble gas among the options provided is Neon (A). Neon belongs to Group 18 on the periodic table and has 10 electrons and 10 neutrons. Its filled outer subshell makes it chemically inert and stable, which is why it is used in lighting systems.